Submission & Review System
Search Article
Search Type
Search Journal
Download CenterMore
3 Status Quo of Methods for Evaluating Filtration Performance and Mud Cake Quality of Drilling Fluid
4 Progresses in Studying Drilling Fluid Nano Material Plugging Agents
5 Drilling Fluid Technology for “Three High” Wells in Qaidam Basin in Qinghai
6 A New Fracturing Fluid with Temperature Resistance of 230℃
7 Synthesis and Evaluation of A Primary Emulsifier for High Temperature Oil Base Drilling Fluid
8 Development of Extreme Pressure Anti-wear Lubricant MPA for Water Base Drilling Fluids
9 Plugging Micro-fractures to Prevent Gas-cut in Fractured Gas Reservoir Drilling
10 A Temperature Sensitive Expanding Microcapsule Anti-Gas-Channeling Cement Slurry
2 Study and Performance Evaluation of Ultra-High Temperature High Density Oil Based Drilling Fluids
3 Synthesis and Evaluation of A Primary Emulsifier for High Temperature Oil Base Drilling Fluid
4 Progresses in Studying Drilling Fluid Nano Material Plugging Agents
5 Hole Cleaning Technology for Horizontal and Deviated Drilling: Progress Made and Prospect
8 High Performance Water Base Drilling Fluid for Shale Gas Drilling
9 A New Fracturing Fluid with Temperature Resistance of 230℃
10 High Performance Water Base Drilling Fluid for Shale Gas Drilling
Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Display Method:
Column
Display Method:
2024, 41(4): 419-426.
doi: 10.12358/j.issn.1001-5620.2024.04.001
Abstract:
Metakaolin has many advantages such as low energy consumption, low calcium content and resistance to CO2 corrosion, and is a potential substitute for conventional silicate cement. By summarizing the progresses made in studying the factors affecting the activity of metakaolin and the alkali-activation reaction, the feasibility of applying metakaolin in well cementing is analyzed. In this paper the factors affecting the activity of metakaolin are summarized, such as calcination temperature, calcination time as well as the aluminum oxide and silica contents of metakaolin. If the calcination temperature is too high or too low, and if the calcination time is too long or too short, the activity of the metakaolin will be low. This paper also introduces the factors affecting the alkali-activation reaction and the components of the products of alkali-activation reaction. It is thought that shortcomings exist in the present research work, and the future researches should be focused on the application of metakaolin in well cementing. In future researches, more attention should be paid to the effects of experimental factors on the thickening time of metakaolin cement slurries and to the methods of how to enhance the compressive strength of the metakaolin slurries without introducing high-calcium materials.
Metakaolin has many advantages such as low energy consumption, low calcium content and resistance to CO2 corrosion, and is a potential substitute for conventional silicate cement. By summarizing the progresses made in studying the factors affecting the activity of metakaolin and the alkali-activation reaction, the feasibility of applying metakaolin in well cementing is analyzed. In this paper the factors affecting the activity of metakaolin are summarized, such as calcination temperature, calcination time as well as the aluminum oxide and silica contents of metakaolin. If the calcination temperature is too high or too low, and if the calcination time is too long or too short, the activity of the metakaolin will be low. This paper also introduces the factors affecting the alkali-activation reaction and the components of the products of alkali-activation reaction. It is thought that shortcomings exist in the present research work, and the future researches should be focused on the application of metakaolin in well cementing. In future researches, more attention should be paid to the effects of experimental factors on the thickening time of metakaolin cement slurries and to the methods of how to enhance the compressive strength of the metakaolin slurries without introducing high-calcium materials.
2024, 41(4): 427-436.
doi: 10.12358/j.issn.1001-5620.2024.04.002
Abstract:
China possesses abundant shale geological reserves and a high concentration of resources in the coastal transition zone. However, drilling operations in this area are susceptible to wall collapse and instability, creating significant risks. This study investigates the mineral composition and microstructure of reservoir rocks through drilling core observation, electron microscopy, CT scanning, and X-ray diffraction analysis. The findings reveal that the shale gas reservoir is predominantly composed of quartz and clay minerals, with a clay mineral content of 45.7%. Notably, montmorillonite is absent, while kaolinite represents 35%, and the illite/montmorillonite mixed layer accounts for 26% of the clay minerals. The rock samples exhibit nano-scale pore development, micro-crack formation with widths in the micron range, and interconnected narrow cracks. Analysis of alterations in interlayer spacing, surface tension, linear expansion rate, and crack expansion after rock-fluid interaction unveils that shale in the coastal transition zone solely undergoes surface hydration, offering insights into the mechanisms of rock-fluid interaction in shale gas reservoirs. Consequently, a high-performance water-based drilling fluid system specifically designed for the coastal transition zone shale gas reservoir is formulated, encompassing the selection of water-based drilling fluid inhibitors, plugging agents, and lubricants. The system is subsequently subject to comprehensive laboratory evaluation, which substantiates its exceptional performance in terms of conventional properties, inhibitory effects, sealing capabilities, and lubrication. It demonstrates a temperature tolerance of up to 100 ℃, experiences a fluid loss of merely 6 mL under high-temperature and high-pressure conditions, exhibits a shale swelling rate of 1.03%, possesses an overall drilling fluid lubrication coefficient of less than 0.15, reduces API filtration loss by 40% compared to the base slurry after 30 min, and effectively seals micro-cracks in the reservoir formations. Additionally, the system demonstrates a low level of biotoxicity, with an EC50 value of 37,260 mg/L. It can meet the requirements of drilling fluid performance for transitional shale gas drilling operations between sea and land, and has been applied on site with good sealing and anti-collapse effects. This research addressing the considerable technical challenge of wall instability in the coastal transition zone shale wells.
China possesses abundant shale geological reserves and a high concentration of resources in the coastal transition zone. However, drilling operations in this area are susceptible to wall collapse and instability, creating significant risks. This study investigates the mineral composition and microstructure of reservoir rocks through drilling core observation, electron microscopy, CT scanning, and X-ray diffraction analysis. The findings reveal that the shale gas reservoir is predominantly composed of quartz and clay minerals, with a clay mineral content of 45.7%. Notably, montmorillonite is absent, while kaolinite represents 35%, and the illite/montmorillonite mixed layer accounts for 26% of the clay minerals. The rock samples exhibit nano-scale pore development, micro-crack formation with widths in the micron range, and interconnected narrow cracks. Analysis of alterations in interlayer spacing, surface tension, linear expansion rate, and crack expansion after rock-fluid interaction unveils that shale in the coastal transition zone solely undergoes surface hydration, offering insights into the mechanisms of rock-fluid interaction in shale gas reservoirs. Consequently, a high-performance water-based drilling fluid system specifically designed for the coastal transition zone shale gas reservoir is formulated, encompassing the selection of water-based drilling fluid inhibitors, plugging agents, and lubricants. The system is subsequently subject to comprehensive laboratory evaluation, which substantiates its exceptional performance in terms of conventional properties, inhibitory effects, sealing capabilities, and lubrication. It demonstrates a temperature tolerance of up to 100 ℃, experiences a fluid loss of merely 6 mL under high-temperature and high-pressure conditions, exhibits a shale swelling rate of 1.03%, possesses an overall drilling fluid lubrication coefficient of less than 0.15, reduces API filtration loss by 40% compared to the base slurry after 30 min, and effectively seals micro-cracks in the reservoir formations. Additionally, the system demonstrates a low level of biotoxicity, with an EC50 value of 37,260 mg/L. It can meet the requirements of drilling fluid performance for transitional shale gas drilling operations between sea and land, and has been applied on site with good sealing and anti-collapse effects. This research addressing the considerable technical challenge of wall instability in the coastal transition zone shale wells.
2024, 41(4): 437-443.
doi: 10.12358/j.issn.1001-5620.2024.04.003
Abstract:
Carbonate reservoirs in the Tahe oilfield are developed with fractures and vugs, drilling into vugs and lost circulation which in turn inducing blowout, borehole wall collapse and stuck pipe have frequently been encountered, and conventional bridging techniques cannot be used to effectively control the mud losses. To deal with the mud loss problem encountered in well workover and completion of old wells, a high temperature polymer gel lost circulation material (LCM) has been developed. Evaluation of the performance of the polymer gel LCM shows that before gelling, the viscosity of the polymer base fluid is in a range of 13 – 14.5 mPa∙s. At 150 ℃, the gelling time of the polymer can be adjusted between 30 min and 150 min. After gelling, the polymer gel loses its mobility and forms a high-strength gel plug. The polymer gel is tested on a 5 cm long iron-made core with 3 mm fractures, which simulates fractures found in the carbonate reservoirs, and a pressure bearing capacity of 2.1 MPa/42 cm is obtained. The polymer gel has good contamination resistance and good stability. The gel of the polymer can be easily broken, by adding alkaline solution into the gel to change the pH value, the gel becomes a low viscosity fluid in 48 h. After gel breaking, the permeability recovery of the rock cores that have been plugged with the gel can be greater than 85%. This high temperature polymer gel can be used to effectively plug formation pores and vugs, it can also be effectively removed away, thus making it a good choice for severe mud losses controlling in workover operations.
Carbonate reservoirs in the Tahe oilfield are developed with fractures and vugs, drilling into vugs and lost circulation which in turn inducing blowout, borehole wall collapse and stuck pipe have frequently been encountered, and conventional bridging techniques cannot be used to effectively control the mud losses. To deal with the mud loss problem encountered in well workover and completion of old wells, a high temperature polymer gel lost circulation material (LCM) has been developed. Evaluation of the performance of the polymer gel LCM shows that before gelling, the viscosity of the polymer base fluid is in a range of 13 – 14.5 mPa∙s. At 150 ℃, the gelling time of the polymer can be adjusted between 30 min and 150 min. After gelling, the polymer gel loses its mobility and forms a high-strength gel plug. The polymer gel is tested on a 5 cm long iron-made core with 3 mm fractures, which simulates fractures found in the carbonate reservoirs, and a pressure bearing capacity of 2.1 MPa/42 cm is obtained. The polymer gel has good contamination resistance and good stability. The gel of the polymer can be easily broken, by adding alkaline solution into the gel to change the pH value, the gel becomes a low viscosity fluid in 48 h. After gel breaking, the permeability recovery of the rock cores that have been plugged with the gel can be greater than 85%. This high temperature polymer gel can be used to effectively plug formation pores and vugs, it can also be effectively removed away, thus making it a good choice for severe mud losses controlling in workover operations.
2024, 41(4): 444-450.
doi: 10.12358/j.issn.1001-5620.2024.04.004
Abstract:
Ultra-deep wells with pressure coefficient less than 1.0 in Tarim oilfield are generally faced with lost circulation of mud in drilling the low-pressured carbonate reservoirs. These wells, with an average depth of over 6,000 m, have high risks of well control, thus, apart from drilling with no return when lost circulation is encountered, no other better means can be used to drill the wells to the designed depths, and in many cases, the wells can only be completed before drilling to the designed depths. To extend the lengths of the horizontal sections of the ultra-deep wells, researchers have developed high strength hollow micro glass beads for formulating water-based drilling fluids with density in a range of 0.93 g/cm3 to 1.07 g/cm3. This paper describes in detail the operation process of the well Zhonggu 262-H4C in which lost circulation was encountered and a low density drilling fluid was then used to regain circulation and drilling was resumed directionally to the designed depth. In the field operation, the density of the drilling fluid was reduced to 0.98 g/cm3, and additional 373 m was drilled after the circulation, realizing the geological goal of one well to penetrate two fractured-vuggy bodies. This measure ensures that the well to be drilled to the designed depth after encountering lost circulation, setting a precedent of drilling an ultra-deep well with vertical depth over 6,000 m using low density drilling fluid formulated with hollow micro glass beads, and providing a technical reference for drilling low-pressured formations in old oilfields in China.
Ultra-deep wells with pressure coefficient less than 1.0 in Tarim oilfield are generally faced with lost circulation of mud in drilling the low-pressured carbonate reservoirs. These wells, with an average depth of over 6,000 m, have high risks of well control, thus, apart from drilling with no return when lost circulation is encountered, no other better means can be used to drill the wells to the designed depths, and in many cases, the wells can only be completed before drilling to the designed depths. To extend the lengths of the horizontal sections of the ultra-deep wells, researchers have developed high strength hollow micro glass beads for formulating water-based drilling fluids with density in a range of 0.93 g/cm3 to 1.07 g/cm3. This paper describes in detail the operation process of the well Zhonggu 262-H4C in which lost circulation was encountered and a low density drilling fluid was then used to regain circulation and drilling was resumed directionally to the designed depth. In the field operation, the density of the drilling fluid was reduced to 0.98 g/cm3, and additional 373 m was drilled after the circulation, realizing the geological goal of one well to penetrate two fractured-vuggy bodies. This measure ensures that the well to be drilled to the designed depth after encountering lost circulation, setting a precedent of drilling an ultra-deep well with vertical depth over 6,000 m using low density drilling fluid formulated with hollow micro glass beads, and providing a technical reference for drilling low-pressured formations in old oilfields in China.
2024, 41(4): 451-457.
doi: 10.12358/j.issn.1001-5620.2024.04.005
Abstract:
Silicate drilling fluids have strong inhibitive capacity and good environment protection property, but their poor lubricity limits their application. In screening good lubricating agents for silicate drilling fluids, extreme pressure (EP) lubrication tester is used to measure the coefficient of friction of silicate drilling fluid samples containing amphiphilic carbon dots and polyoxyethylene surfactant. The best lubricating agent selected is then tested with total organic carbon analyzer, dynamic light scattering tester and contact angle tester to analyze its mechanisms of lubrication. The test results show that the amphiphilic cardon dots have excellent lubricity and high temperature stability. A 5% sodium silicate (Na2SiO3) water solution treated has EP coefficient of friction of around 0.500. The solution is then treated with 0.3% amphiphilic carbon dots (C12-CDs), and the EP coefficient of friction is reduced to 0.065. After hot rolling the C12-CDs treated Na2SiO3 solution at 110 ℃ for 16 h, the EP coefficient of friction of the solution is further reduced to 0.063, that is, the EP coefficient of friction of the Na2SiO3 solution is reduced by 87.52%. On the other hand, the polyoxyethylene surfactant shows no effect on the lubricity of the Na2SiO3 solution. Further study shows that C12-CDs has excellent adsorption performance on the surface of the quartz sands, the surface tension of a C12-CDs solution (c = 100 mg/L) increases from 44.81 mN/m before the adsorption process to 64.03 mN/m after the adsorption process, the adsorption capacity is 89.23 mg/L. Particle size analysis shows that the C12-CDs can effectively reduce the particle sizes of the Na2SiO3 solution; the average particle size of the Na2SiO3 solution is reduced from 514 nm to 63.2 nm. The multi-hydroxy structure and the long hydrophobic chain on the surface of the carbon nuclei can improve the adsorption of the amphiphilic carbon dots on the surfaces of the drill string, the borehole walls and the silicate aggregates. The amphiphilic carbon dots as a good lubricating agent have good compatibility with silicate drilling fluids. Field application shows that C12-CDs can reduce the coefficient of friction of silicate drilling fluids by 86.34%, and are thus a good lubricating agent for silicate drilling fluids.
Silicate drilling fluids have strong inhibitive capacity and good environment protection property, but their poor lubricity limits their application. In screening good lubricating agents for silicate drilling fluids, extreme pressure (EP) lubrication tester is used to measure the coefficient of friction of silicate drilling fluid samples containing amphiphilic carbon dots and polyoxyethylene surfactant. The best lubricating agent selected is then tested with total organic carbon analyzer, dynamic light scattering tester and contact angle tester to analyze its mechanisms of lubrication. The test results show that the amphiphilic cardon dots have excellent lubricity and high temperature stability. A 5% sodium silicate (Na2SiO3) water solution treated has EP coefficient of friction of around 0.500. The solution is then treated with 0.3% amphiphilic carbon dots (C12-CDs), and the EP coefficient of friction is reduced to 0.065. After hot rolling the C12-CDs treated Na2SiO3 solution at 110 ℃ for 16 h, the EP coefficient of friction of the solution is further reduced to 0.063, that is, the EP coefficient of friction of the Na2SiO3 solution is reduced by 87.52%. On the other hand, the polyoxyethylene surfactant shows no effect on the lubricity of the Na2SiO3 solution. Further study shows that C12-CDs has excellent adsorption performance on the surface of the quartz sands, the surface tension of a C12-CDs solution (c = 100 mg/L) increases from 44.81 mN/m before the adsorption process to 64.03 mN/m after the adsorption process, the adsorption capacity is 89.23 mg/L. Particle size analysis shows that the C12-CDs can effectively reduce the particle sizes of the Na2SiO3 solution; the average particle size of the Na2SiO3 solution is reduced from 514 nm to 63.2 nm. The multi-hydroxy structure and the long hydrophobic chain on the surface of the carbon nuclei can improve the adsorption of the amphiphilic carbon dots on the surfaces of the drill string, the borehole walls and the silicate aggregates. The amphiphilic carbon dots as a good lubricating agent have good compatibility with silicate drilling fluids. Field application shows that C12-CDs can reduce the coefficient of friction of silicate drilling fluids by 86.34%, and are thus a good lubricating agent for silicate drilling fluids.
2024, 41(4): 458-466.
doi: 10.12358/j.issn.1001-5620.2024.04.006
Abstract:
In underground diaphragm wall and pile foundation engineering operations, calcium ions from the concrete continually invade into the drilling fluids because of the frequent contact of the drilling fluids with the concrete, leading to gradual deterioration of the basic properties of the drilling fluids and large amount of waste muds after the operations. To improve the calcium resistance of the drilling fluids and minimize the amount of waste drilling fluids produced, the natural bentonite used to formulate the drilling fluids needs to be modified. A calcium-resistant compound bentonite ACB-16 is synthesized with natural bentonite purified through high-speed centrifuging and monomers for polymerization, such as a hydrophilic monomer BX with double carbon bonds, hydrophilic monomers AS and AP with sulfonic acid groups. In the polymerization reaction, the monomers enter into the crystal spaces of the purified bentonite, reacting with each other through in-situ free radical polymerization. Studies on the polymerization products with FT-IR, particle size distribution test, SEM and TEM show that the monomers successfully in-situ polymerize in the crystal spaces of the bentonite. The quality of ACB-16 exceeds the quality of the OCMA bentonite. A drilling fluid formulated with ACB-16 has an apparent viscosity of 26 mPa∙s, an API filter loss of 7.6 mL, a good rheology and filtration property as well as a good calcium resistance. When contaminated with 1% calcium chloride, the rheology and filtration property of the drilling fluid are still stable. The limit of calcium resistance of a drilling fluid formulated with ACB-16 is 6,300 mg/L (equivalent to 1.75% CaCl2), perfectly satisfying the requirements for a drilling fluid to resist calcium contamination in foundation engineering. Using particle size analysis and SEM, the working mechanism of ACB-16 is studied. The high molecular weight polymers located on the networking structures of the bentonite hinder the ion exchange between the calcium ions and the bentonite, thereby maintaining the thickness of the hydration membrane and the c-spacing of the bentonite and supporting the network structures generated by the hydrated bentonite. Direct mixing of ACB-16 with water can obtain a calcium-resistant drilling fluid with excellent properties. ACB-16 is easy to use, it will have good application prospects in foundation engineering and other fields, and it can also be used in formulating anti-sloughing drilling fluids for high calcium environment such as salt and gypsum drilling.
In underground diaphragm wall and pile foundation engineering operations, calcium ions from the concrete continually invade into the drilling fluids because of the frequent contact of the drilling fluids with the concrete, leading to gradual deterioration of the basic properties of the drilling fluids and large amount of waste muds after the operations. To improve the calcium resistance of the drilling fluids and minimize the amount of waste drilling fluids produced, the natural bentonite used to formulate the drilling fluids needs to be modified. A calcium-resistant compound bentonite ACB-16 is synthesized with natural bentonite purified through high-speed centrifuging and monomers for polymerization, such as a hydrophilic monomer BX with double carbon bonds, hydrophilic monomers AS and AP with sulfonic acid groups. In the polymerization reaction, the monomers enter into the crystal spaces of the purified bentonite, reacting with each other through in-situ free radical polymerization. Studies on the polymerization products with FT-IR, particle size distribution test, SEM and TEM show that the monomers successfully in-situ polymerize in the crystal spaces of the bentonite. The quality of ACB-16 exceeds the quality of the OCMA bentonite. A drilling fluid formulated with ACB-16 has an apparent viscosity of 26 mPa∙s, an API filter loss of 7.6 mL, a good rheology and filtration property as well as a good calcium resistance. When contaminated with 1% calcium chloride, the rheology and filtration property of the drilling fluid are still stable. The limit of calcium resistance of a drilling fluid formulated with ACB-16 is 6,300 mg/L (equivalent to 1.75% CaCl2), perfectly satisfying the requirements for a drilling fluid to resist calcium contamination in foundation engineering. Using particle size analysis and SEM, the working mechanism of ACB-16 is studied. The high molecular weight polymers located on the networking structures of the bentonite hinder the ion exchange between the calcium ions and the bentonite, thereby maintaining the thickness of the hydration membrane and the c-spacing of the bentonite and supporting the network structures generated by the hydrated bentonite. Direct mixing of ACB-16 with water can obtain a calcium-resistant drilling fluid with excellent properties. ACB-16 is easy to use, it will have good application prospects in foundation engineering and other fields, and it can also be used in formulating anti-sloughing drilling fluids for high calcium environment such as salt and gypsum drilling.
2024, 41(4): 467-472.
doi: 10.12358/j.issn.1001-5620.2024.04.007
Abstract:
In recent years, with the increase of high-yield industrial gas flow wells in the Qingshimao area, this area has The Qingshimao block in recent years has become a high gas production area and will be the next important exploration block in Changqing Oilfield. Geologically the Qingshimao block belongs to the Tianhuan depression in Erdos Basin, with more and more deep exploratory wells drilled in recent years, lost circulation, especially severe mud losses in deep surface section of a well, has been more frequently encountered during drilling. The severe lost circulation is mainly encountered in the Quaternary System in which formation waters are very active, and conventional techniques for controlling the lost circulation are rarely effective. The Luohandong formation, on the other hand, has long section of continuously fractured formation, and the lost circulation is frequently encountered and the treatment is time-consuming. In dealing with mud losses in shallower water-bearing formations, a lost circulation slurry that expands when in contact with water is used to control mud losses. Large particles that can control the rate of mud losses have been developed and used to ensure one trip of drilling through the whole length of fractures. When drilling into stable formations, cementable lost circulation slurries with wide particle size distribution can be used to plug and seal off the long section of fractured formations. These practices have formed a special technology for controlling mud losses encountered in drilling the deep surface hole in the strike-slip fault zone in the Tianhuan depression in Erdos Basin. This technology has been successfully used in the Qingshimao block, and several wells with deep surface holes have been successfully drilled.
In recent years, with the increase of high-yield industrial gas flow wells in the Qingshimao area, this area has The Qingshimao block in recent years has become a high gas production area and will be the next important exploration block in Changqing Oilfield. Geologically the Qingshimao block belongs to the Tianhuan depression in Erdos Basin, with more and more deep exploratory wells drilled in recent years, lost circulation, especially severe mud losses in deep surface section of a well, has been more frequently encountered during drilling. The severe lost circulation is mainly encountered in the Quaternary System in which formation waters are very active, and conventional techniques for controlling the lost circulation are rarely effective. The Luohandong formation, on the other hand, has long section of continuously fractured formation, and the lost circulation is frequently encountered and the treatment is time-consuming. In dealing with mud losses in shallower water-bearing formations, a lost circulation slurry that expands when in contact with water is used to control mud losses. Large particles that can control the rate of mud losses have been developed and used to ensure one trip of drilling through the whole length of fractures. When drilling into stable formations, cementable lost circulation slurries with wide particle size distribution can be used to plug and seal off the long section of fractured formations. These practices have formed a special technology for controlling mud losses encountered in drilling the deep surface hole in the strike-slip fault zone in the Tianhuan depression in Erdos Basin. This technology has been successfully used in the Qingshimao block, and several wells with deep surface holes have been successfully drilled.
2024, 41(4): 473-480.
doi: 10.12358/j.issn.1001-5620.2024.04.008
Abstract:
Two wells, the well Long-XX and the well Ning-XX, in Longdong area are recently tested, and the target zone located in the bauxite formation has been found an important alternative resource for the Changqing Oilfield. Significant findings were obtained in exploring the bauxite formation through these two wells. Technical difficulties, such as prevailing of dissolution pores and fractures, borehole wall collapse, mud losses and poor hole cleaning etc. have been encountered in drilling the target bauxite formation. The main factors contributing to borehole wall collapse were found in analyzing and testing the bauxite samples for physical properties, chemical properties, mechanical properties and sensitivity characteristics, and a fast-plugging, inhibitive drilling fluid for safe drilling of the bauxite formation was developed. This drilling fluid has high temperature (170 ℃) high pressure filter loss of less than 10 mL and percent secondary cuttings recovery of greater than 91%. After soaking the bauxite samples in the drilling fluid and fresh water respectively for 15 days, the compressive strength of the samples tested in the drilling fluid is 81.8% higher than that of the samples tested in the fresh water. This drilling fluid has been tried in drilling the first horizontal Long-4XX well targeted the bauxite reservoir in Changqing, a horizontal section of 700 m was successfully drilled. The daily flowing production rate of this well is 3.53 × 106 m3, a new record made in developing the upper Paleozoic resources in the Erdos basin in the last 50 more years. This technology has provided a technical support to the development of the similar reservoirs.
Two wells, the well Long-XX and the well Ning-XX, in Longdong area are recently tested, and the target zone located in the bauxite formation has been found an important alternative resource for the Changqing Oilfield. Significant findings were obtained in exploring the bauxite formation through these two wells. Technical difficulties, such as prevailing of dissolution pores and fractures, borehole wall collapse, mud losses and poor hole cleaning etc. have been encountered in drilling the target bauxite formation. The main factors contributing to borehole wall collapse were found in analyzing and testing the bauxite samples for physical properties, chemical properties, mechanical properties and sensitivity characteristics, and a fast-plugging, inhibitive drilling fluid for safe drilling of the bauxite formation was developed. This drilling fluid has high temperature (170 ℃) high pressure filter loss of less than 10 mL and percent secondary cuttings recovery of greater than 91%. After soaking the bauxite samples in the drilling fluid and fresh water respectively for 15 days, the compressive strength of the samples tested in the drilling fluid is 81.8% higher than that of the samples tested in the fresh water. This drilling fluid has been tried in drilling the first horizontal Long-4XX well targeted the bauxite reservoir in Changqing, a horizontal section of 700 m was successfully drilled. The daily flowing production rate of this well is 3.53 × 106 m3, a new record made in developing the upper Paleozoic resources in the Erdos basin in the last 50 more years. This technology has provided a technical support to the development of the similar reservoirs.
2024, 41(4): 481-488.
doi: 10.12358/j.issn.1001-5620.2024.04.009
Abstract:
Lost circulation during drilling is a downhole problem frequently encountered in the Chuanyu area, and in part of the area, severe lost circulation encountered in complex formations can only be cured after several times of operation and with different lost circulation control techniques, resulting in high drilling cost. By analyzing the lost circulation control techniques used in the past, a one-sack temperature-control gel-type resin lost circulation material (LCM) YDFD was developed based on the principles of bridging and packing in fractures. The raw materials in producing the LCM YDFD include a high-strength equilateral tetrahedron resin as the main bridging material, a flaky resin and a thermo-set resin as the packing material, and a fiber material, and these three materials, by entanglement crosslinking, produce the final product YDFD. In lost circulation control, three models of YDFD, which are small, medium and large, are mixed in a certain ratio to combat mud losses of different rates such as mud losses into small fractures, vugs, big fractures and another type of mud loss called breathing loss. Into the LCM slurry a temperature control agent is used to regulate the time required for the LCM slurry to solidify, thereby ensuring safe operation and accurate plugging of the channels into which mud is lost. In controlling lost circulation with the YDFD LCM in the Chuanyu area, 93% mud losses are successfully brought under control in the first try. This technique is worth trying in combating mud losses in oil and gas development.
Lost circulation during drilling is a downhole problem frequently encountered in the Chuanyu area, and in part of the area, severe lost circulation encountered in complex formations can only be cured after several times of operation and with different lost circulation control techniques, resulting in high drilling cost. By analyzing the lost circulation control techniques used in the past, a one-sack temperature-control gel-type resin lost circulation material (LCM) YDFD was developed based on the principles of bridging and packing in fractures. The raw materials in producing the LCM YDFD include a high-strength equilateral tetrahedron resin as the main bridging material, a flaky resin and a thermo-set resin as the packing material, and a fiber material, and these three materials, by entanglement crosslinking, produce the final product YDFD. In lost circulation control, three models of YDFD, which are small, medium and large, are mixed in a certain ratio to combat mud losses of different rates such as mud losses into small fractures, vugs, big fractures and another type of mud loss called breathing loss. Into the LCM slurry a temperature control agent is used to regulate the time required for the LCM slurry to solidify, thereby ensuring safe operation and accurate plugging of the channels into which mud is lost. In controlling lost circulation with the YDFD LCM in the Chuanyu area, 93% mud losses are successfully brought under control in the first try. This technique is worth trying in combating mud losses in oil and gas development.
2024, 41(4): 489-495.
doi: 10.12358/j.issn.1001-5620.2024.04.010
Abstract:
In well cementing operation, a certain amount of spacer needs to be pumped into the wellbore before injecting cement slurries. In offshore well cementing, the preparation of spacer requires heavy manual labor, and the labor intensity is quite high, resulting in low operation efficiency and poor control on the quantities of the spacer additives. To solve this problem, liquid additives are used to replace the solids additives in formulating the spacer, and the liquid additives are added through the additive addition system LAS. Using this technique, the traditional heavy physical labor in formulating a spacer is replaced with intelligent operation, the labor intensity is lowered, the efficiency of well cementing operation is increased, and the labor costs are reduced. A liquid spacer additive C-S70L is prepared through inverse emulsion polymerization. Using C-S70L as the core additive, a spacer suitable for injection using the LAS is formulated. This spacer can be used in temperature range of 20 - 120 °C and density range of 1.30 – 1.70 g/cm3. It has good suspending stability (no settling after hot rolling), a rheology that is easy to adjust, a fluid loss that is controllable and good compatibility.
In well cementing operation, a certain amount of spacer needs to be pumped into the wellbore before injecting cement slurries. In offshore well cementing, the preparation of spacer requires heavy manual labor, and the labor intensity is quite high, resulting in low operation efficiency and poor control on the quantities of the spacer additives. To solve this problem, liquid additives are used to replace the solids additives in formulating the spacer, and the liquid additives are added through the additive addition system LAS. Using this technique, the traditional heavy physical labor in formulating a spacer is replaced with intelligent operation, the labor intensity is lowered, the efficiency of well cementing operation is increased, and the labor costs are reduced. A liquid spacer additive C-S70L is prepared through inverse emulsion polymerization. Using C-S70L as the core additive, a spacer suitable for injection using the LAS is formulated. This spacer can be used in temperature range of 20 - 120 °C and density range of 1.30 – 1.70 g/cm3. It has good suspending stability (no settling after hot rolling), a rheology that is easy to adjust, a fluid loss that is controllable and good compatibility.
2016, 33(1): 6-10.
doi: 10.3969/j.issn.1001-5620.2016.01.002
摘要：
以妥尔油脂肪酸和马来酸酐为主要原料合成了一种油基钻井液抗高温主乳化剂HT-MUL,并确定了妥尔油脂肪酸单体的最佳酸值及马来酸酐单体的最优加量。对HT-MUL进行了单剂评价,结果表明HT-MUL的乳化能力良好,配制的油水比为60:40的油包水乳液的破乳电压最高可达490 V,90:10的乳液破乳电压最高可达1000 V。从抗温性、滤失性、乳化率方面对HT-MUL和国内外同类产品进行了对比,结果表明HT-MUL配制的乳液破乳电压更大、滤失量更小、乳化率更高,整体性能优于国内外同类产品。应用主乳化剂HT-MUL配制了高密度的油基钻井液,其性能评价表明体系的基本性能良好,在220℃高温热滚后、破乳电压高达800 V,滤失量低于5 mL。HT-MUL配制的油基钻井液具有良好的抗高温性和乳化稳定性。
以妥尔油脂肪酸和马来酸酐为主要原料合成了一种油基钻井液抗高温主乳化剂HT-MUL,并确定了妥尔油脂肪酸单体的最佳酸值及马来酸酐单体的最优加量。对HT-MUL进行了单剂评价,结果表明HT-MUL的乳化能力良好,配制的油水比为60:40的油包水乳液的破乳电压最高可达490 V,90:10的乳液破乳电压最高可达1000 V。从抗温性、滤失性、乳化率方面对HT-MUL和国内外同类产品进行了对比,结果表明HT-MUL配制的乳液破乳电压更大、滤失量更小、乳化率更高,整体性能优于国内外同类产品。应用主乳化剂HT-MUL配制了高密度的油基钻井液,其性能评价表明体系的基本性能良好,在220℃高温热滚后、破乳电压高达800 V,滤失量低于5 mL。HT-MUL配制的油基钻井液具有良好的抗高温性和乳化稳定性。
2016, 33(5): 1-8.
doi: 10.3969/j.issn.1001-5620.2016.05.001
摘要：
综述了国内外页岩气井井壁失稳机理、稳定井壁主要方法及水基钻井液技术研究与应用现状，讨论了当前中国页岩气井钻井液技术面临的主要技术难题，分析了美国页岩气井与中国主要页岩气产区井壁失稳机理的差异，指出了中国页岩气井水基钻井液技术研究存在的误区与不足，提出了中国页岩气井水基钻井液技术发展方向。
综述了国内外页岩气井井壁失稳机理、稳定井壁主要方法及水基钻井液技术研究与应用现状，讨论了当前中国页岩气井钻井液技术面临的主要技术难题，分析了美国页岩气井与中国主要页岩气产区井壁失稳机理的差异，指出了中国页岩气井水基钻井液技术研究存在的误区与不足，提出了中国页岩气井水基钻井液技术发展方向。
2018, 35(2): 1-16.
doi: 10.3969/j.issn.1001-5620.2018.02.001
摘要：
通常在勘探开发油气过程中会发生不同程度的油气层损害，导致产量下降、甚至"枪毙"油气层等，钻井液是第一个与油气层相接触的外来流体，引起的油气层损害程度往往较大。为减轻或避免钻井液导致的油气层损害、提高单井产量，国内外学者们进行了长达半个世纪以上的研究工作，先后建立了"屏蔽暂堵、精细暂堵、物理化学膜暂堵"三代暂堵型保护油气层钻井液技术，使保护油气层效果逐步提高，经济效益明显。但是，与石油工程师们追求的"超低"损害目标仍存在一定差距，特别是随着非常规、复杂、超深层、超深水等类型油气层勘探开发力度的加大，以前的保护技术难以满足要求。为此，将仿生学引入保护油气层钻井液理论中，发展了适合不同油气层渗透率大小的"超双疏、生物膜、协同增效"仿生技术，并在各大油田得到推广应用，达到了"超低"损害目标，标志着第四代暂堵型保护油气层钻井液技术的建立。对上述4代暂堵型保护油气层技术的理论基础、实施方案、室内评价、现场应用效果与优缺点等进行了论述，并通过梳理阐明了将来的研究方向与发展趋势，对现场技术人员和科技工作者具有较大指导意义。
通常在勘探开发油气过程中会发生不同程度的油气层损害，导致产量下降、甚至"枪毙"油气层等，钻井液是第一个与油气层相接触的外来流体，引起的油气层损害程度往往较大。为减轻或避免钻井液导致的油气层损害、提高单井产量，国内外学者们进行了长达半个世纪以上的研究工作，先后建立了"屏蔽暂堵、精细暂堵、物理化学膜暂堵"三代暂堵型保护油气层钻井液技术，使保护油气层效果逐步提高，经济效益明显。但是，与石油工程师们追求的"超低"损害目标仍存在一定差距，特别是随着非常规、复杂、超深层、超深水等类型油气层勘探开发力度的加大，以前的保护技术难以满足要求。为此，将仿生学引入保护油气层钻井液理论中，发展了适合不同油气层渗透率大小的"超双疏、生物膜、协同增效"仿生技术，并在各大油田得到推广应用，达到了"超低"损害目标，标志着第四代暂堵型保护油气层钻井液技术的建立。对上述4代暂堵型保护油气层技术的理论基础、实施方案、室内评价、现场应用效果与优缺点等进行了论述，并通过梳理阐明了将来的研究方向与发展趋势，对现场技术人员和科技工作者具有较大指导意义。
2016, 33(1): 33-36.
doi: 10.3969/j.issn.1001-5620.2016.01.007
摘要：
页岩具有极低的渗透率和极小的孔喉尺寸,传统封堵剂难以在页岩表面形成有效的泥饼,只有纳米级颗粒才能封堵页岩的孔喉,阻止液相侵入地层,维持井壁稳定,保护储层。以苯乙烯(St)、甲基丙烯酸甲酯(MMA)为单体,过硫酸钾(KPS)为引发剂,采用乳液聚合法制备了纳米聚合物微球封堵剂SD-seal。通过红外光谱、透射电镜、热重分析和激光粒度分析对产物进行了表征,通过龙马溪组岩样的压力传递实验研究了其封堵性能。结果表明,SD-seal纳米粒子分散性好,形状规则(基本为球形),粒度较均匀(20 nm左右),分解温度高达402.5℃,热稳定性好,阻缓压力传递效果显著,使龙马溪组页岩岩心渗透率降低95%。
页岩具有极低的渗透率和极小的孔喉尺寸,传统封堵剂难以在页岩表面形成有效的泥饼,只有纳米级颗粒才能封堵页岩的孔喉,阻止液相侵入地层,维持井壁稳定,保护储层。以苯乙烯(St)、甲基丙烯酸甲酯(MMA)为单体,过硫酸钾(KPS)为引发剂,采用乳液聚合法制备了纳米聚合物微球封堵剂SD-seal。通过红外光谱、透射电镜、热重分析和激光粒度分析对产物进行了表征,通过龙马溪组岩样的压力传递实验研究了其封堵性能。结果表明,SD-seal纳米粒子分散性好,形状规则(基本为球形),粒度较均匀(20 nm左右),分解温度高达402.5℃,热稳定性好,阻缓压力传递效果显著,使龙马溪组页岩岩心渗透率降低95%。
2016, 33(4): 74-78.
doi: 10.3969/j.issn.1001-5620.2016.04.015
摘要：
利用自主研发的水泥环密封性实验装置研究了套管内加卸压循环作用下水泥环的密封性，根据实验结果得出了循环应力作用下水泥环密封性失效的机理。实验结果显示，在较低套管内压循环作用下，水泥环保持密封性所能承受的应力循环次数较多；在较高循环应力作用下，水泥环密封性失效时循环次数较少。表明在套管内较低压力作用下，水泥环所受的应力较低，应力水平处于弹性状态，在加卸载的循环作用下，水泥环可随之弹性变形和弹性恢复；在较高应力作用下，水泥环内部固有的微裂纹和缺陷逐渐扩展和连通，除了发生弹性变形还产生了塑性变形；随着应力循环次数的增加，塑性变形也不断地累积。循环压力卸载时，套管弹性回缩而水泥环塑性变形不可完全恢复，2者在界面处的变形不协调而引起拉应力。当拉应力超过界面处的胶结强度时出现微环隙，导致水泥环密封性失效，水泥环发生循环应力作用的低周期密封性疲劳破坏。套管内压力越大，水泥环中产生的应力水平越高，产生的塑性变形越大，每次卸载时产生的残余应变和界面处拉应力也越大，因此引起密封性失效的应力循环次数越少。
利用自主研发的水泥环密封性实验装置研究了套管内加卸压循环作用下水泥环的密封性，根据实验结果得出了循环应力作用下水泥环密封性失效的机理。实验结果显示，在较低套管内压循环作用下，水泥环保持密封性所能承受的应力循环次数较多；在较高循环应力作用下，水泥环密封性失效时循环次数较少。表明在套管内较低压力作用下，水泥环所受的应力较低，应力水平处于弹性状态，在加卸载的循环作用下，水泥环可随之弹性变形和弹性恢复；在较高应力作用下，水泥环内部固有的微裂纹和缺陷逐渐扩展和连通，除了发生弹性变形还产生了塑性变形；随着应力循环次数的增加，塑性变形也不断地累积。循环压力卸载时，套管弹性回缩而水泥环塑性变形不可完全恢复，2者在界面处的变形不协调而引起拉应力。当拉应力超过界面处的胶结强度时出现微环隙，导致水泥环密封性失效，水泥环发生循环应力作用的低周期密封性疲劳破坏。套管内压力越大，水泥环中产生的应力水平越高，产生的塑性变形越大，每次卸载时产生的残余应变和界面处拉应力也越大，因此引起密封性失效的应力循环次数越少。
2017, 34(1): 1-8.
doi: 10.3969/j.issn.1001-5620.2017.01.001
摘要：
分析了硬脆性泥页岩井壁失稳的原因，介绍了纳米材料特点及其应用，并概述了国内外钻井液用纳米封堵剂的研究进展，包括有机纳米封堵剂、无机纳米封堵剂、有机/无机纳米封堵剂，以及纳米封堵剂现场应用案例。笔者认为：利用无机纳米材料刚性特征以及有机聚合物可任意变形、支化成膜等特性，形成的一种核壳结构的无机/聚合物类纳米封堵剂，能够很好地分散到钻井液中，且对钻井液黏度和切力影响较小，这种类型的纳米封堵剂能够在低浓度下封堵泥页岩孔喉，建立一种疏水型且具有一定强度的泥页岩人工井壁，这不仅能够阻止钻井液侵入，而且还能提高地层承压能力，无机纳米材料与有机聚合物的结合是未来钻井液防塌剂的发展方向。
分析了硬脆性泥页岩井壁失稳的原因，介绍了纳米材料特点及其应用，并概述了国内外钻井液用纳米封堵剂的研究进展，包括有机纳米封堵剂、无机纳米封堵剂、有机/无机纳米封堵剂，以及纳米封堵剂现场应用案例。笔者认为：利用无机纳米材料刚性特征以及有机聚合物可任意变形、支化成膜等特性，形成的一种核壳结构的无机/聚合物类纳米封堵剂，能够很好地分散到钻井液中，且对钻井液黏度和切力影响较小，这种类型的纳米封堵剂能够在低浓度下封堵泥页岩孔喉，建立一种疏水型且具有一定强度的泥页岩人工井壁，这不仅能够阻止钻井液侵入，而且还能提高地层承压能力，无机纳米材料与有机聚合物的结合是未来钻井液防塌剂的发展方向。
2016, 33(1): 17-21.
doi: 10.3969/j.issn.1001-5620.2016.01.004
摘要：
目前中国页岩气水平井定向段及水平段钻井均使用油基钻井液,但油基岩屑处理费用昂贵,急需开发和应用一种具有环境保护特性的高性能水基钻井液体系。介绍了2种高性能水基钻井液体系的室内实验和现场试验效果。在长宁H9-4井水平段、长宁H9-3和长宁H9-5井定向至完井段试验了GOF高性能水基钻井液体系,该体系采用的是聚合物封堵抑制方案,完全采用水基润滑方式;在昭通区块YS108H4-2井水平段试验了高润强抑制性水基钻井液体系,该体系采用的是有机、无机盐复合防膨方案以及润滑剂与柴油复合润滑方式。现场应用表明,定向段机械钻速提高50%~75%,水平段机械钻速提高75%~100%。通过实验数据及现场使用情况,对比分析了2种体系的优劣,找出了他们各自存在的问题,并提出了改进的思路,为高性能水基钻井液的进一步完善提供一些经验。
目前中国页岩气水平井定向段及水平段钻井均使用油基钻井液,但油基岩屑处理费用昂贵,急需开发和应用一种具有环境保护特性的高性能水基钻井液体系。介绍了2种高性能水基钻井液体系的室内实验和现场试验效果。在长宁H9-4井水平段、长宁H9-3和长宁H9-5井定向至完井段试验了GOF高性能水基钻井液体系,该体系采用的是聚合物封堵抑制方案,完全采用水基润滑方式;在昭通区块YS108H4-2井水平段试验了高润强抑制性水基钻井液体系,该体系采用的是有机、无机盐复合防膨方案以及润滑剂与柴油复合润滑方式。现场应用表明,定向段机械钻速提高50%~75%,水平段机械钻速提高75%~100%。通过实验数据及现场使用情况,对比分析了2种体系的优劣,找出了他们各自存在的问题,并提出了改进的思路,为高性能水基钻井液的进一步完善提供一些经验。
2016, 33(6): 121-126.
doi: 10.3969/j.issn.1001-5620.2016.06.022
摘要：
统计长庆油田罗*区块2015年存地液量与油井一年累积产量的关系发现，存地液量越大，一年累积产量越高，与常规的返排率越高产量越高概念恰恰相反，可能与存地液的自发渗吸替油有关。核磁实验结果表明，渗吸替油不同于驱替作用，渗吸过程中小孔隙对采出程度贡献大，而驱替过程中大孔隙对采出程度贡献大，但从现场致密储层岩心孔隙度来看，储层驱替效果明显弱于渗吸效果。通过实验研究了影响自发渗吸效率因素，探索影响压裂液油水置换的关键影响因素，得出了最佳渗吸采出率及最大渗吸速度现场参数。结果表明，各参数对渗吸速度的影响顺序为：界面张力 > 渗透率 > 原油黏度 > 矿化度,岩心渗透率越大，渗吸采收率越大，但是增幅逐渐减小；原油黏度越小，渗吸采收率越大；渗吸液矿化度越大，渗吸采收率越大；当渗吸液中助排剂浓度在0.005%~5%，即界面张力在0.316~10.815 mN/m范围内时，浓度为0.5%（界面张力为0.869 mN/m）的渗吸液可以使渗吸采收率达到最大。静态渗吸结果表明：并不是界面张力越低，采收率越高，而是存在某一最佳界面张力，使地层中被绕流油的数量减少，渗吸采收率达到最高，为油田提高致密储层采收率提供实验指导。
统计长庆油田罗*区块2015年存地液量与油井一年累积产量的关系发现，存地液量越大，一年累积产量越高，与常规的返排率越高产量越高概念恰恰相反，可能与存地液的自发渗吸替油有关。核磁实验结果表明，渗吸替油不同于驱替作用，渗吸过程中小孔隙对采出程度贡献大，而驱替过程中大孔隙对采出程度贡献大，但从现场致密储层岩心孔隙度来看，储层驱替效果明显弱于渗吸效果。通过实验研究了影响自发渗吸效率因素，探索影响压裂液油水置换的关键影响因素，得出了最佳渗吸采出率及最大渗吸速度现场参数。结果表明，各参数对渗吸速度的影响顺序为：界面张力 > 渗透率 > 原油黏度 > 矿化度,岩心渗透率越大，渗吸采收率越大，但是增幅逐渐减小；原油黏度越小，渗吸采收率越大；渗吸液矿化度越大，渗吸采收率越大；当渗吸液中助排剂浓度在0.005%~5%，即界面张力在0.316~10.815 mN/m范围内时，浓度为0.5%（界面张力为0.869 mN/m）的渗吸液可以使渗吸采收率达到最大。静态渗吸结果表明：并不是界面张力越低，采收率越高，而是存在某一最佳界面张力，使地层中被绕流油的数量减少，渗吸采收率达到最高，为油田提高致密储层采收率提供实验指导。
2020, 37(1): 1-8.
doi: 10.3969/j.issn.1001-5620.2020.01.001
摘要：
废弃钻井液污染大、种类多、处理难，给水质和土壤环境带来巨大的负面影响，随着近些年环保法规的日益完善，对废弃钻井液的处理技术也提出了新要求。概述了9种不同处理方法及其发展现状，重点分析了固化法、热解吸法、化学强化固液分离法、不落地技术和多种技术联用等处理技术，并对几种现行的主流处理技术进行了对比，指出了各类方法的发展前景，得出多种技术联用具有较好的发展潜力。分析认为今后的研究方向与热点在于如何低能耗、高效率地实现对废弃钻井液的资源化处理，具体工作既要包含污染物的源头、过程和结果控制，也要加强管理和相关制度的建立，综合开发新技术。
废弃钻井液污染大、种类多、处理难，给水质和土壤环境带来巨大的负面影响，随着近些年环保法规的日益完善，对废弃钻井液的处理技术也提出了新要求。概述了9种不同处理方法及其发展现状，重点分析了固化法、热解吸法、化学强化固液分离法、不落地技术和多种技术联用等处理技术，并对几种现行的主流处理技术进行了对比，指出了各类方法的发展前景，得出多种技术联用具有较好的发展潜力。分析认为今后的研究方向与热点在于如何低能耗、高效率地实现对废弃钻井液的资源化处理，具体工作既要包含污染物的源头、过程和结果控制，也要加强管理和相关制度的建立，综合开发新技术。
2017, 34(1): 54-59.
doi: 10.3969/j.issn.1001-5620.2017.01.010
摘要：
库车山前深部巨厚盐膏层地质特征复杂，层间超高压盐水普遍发育，纵横向规律性差，地层压力变化大，预测难度高。盐膏层钻井过程中超高压盐水侵入井筒后，钻井液性能恶化，导致喷、漏、卡等复杂事故频发，严重影响安全快速钻井。结合超高压盐水层钻井特征，通过分析超高压盐水赋存的圈闭特点及实钻情况，在钻井液的盐水污染容量限实验模拟和评价的基础上，开展了超高压盐水层控压排水技术的探索与实践，形成了控压排水配套新技术，通过控制节流阀调节井口回压和钻井液排量等手段，让地层盐水按一定比例均匀侵入到环空钻井液中，单次放水量不超过环空钻井液量的10%，多次放出盐水，降低高压盐水层的地层压力系数。解决了库车山前超深超高压盐水层安全钻井难题。现场试验表明，采取合理的控压排水方法能够降低盐水层的压力，在溢流与井漏的矛盾中找到压力平衡点，有利于井控安全的井筒状态。
库车山前深部巨厚盐膏层地质特征复杂，层间超高压盐水普遍发育，纵横向规律性差，地层压力变化大，预测难度高。盐膏层钻井过程中超高压盐水侵入井筒后，钻井液性能恶化，导致喷、漏、卡等复杂事故频发，严重影响安全快速钻井。结合超高压盐水层钻井特征，通过分析超高压盐水赋存的圈闭特点及实钻情况，在钻井液的盐水污染容量限实验模拟和评价的基础上，开展了超高压盐水层控压排水技术的探索与实践，形成了控压排水配套新技术，通过控制节流阀调节井口回压和钻井液排量等手段，让地层盐水按一定比例均匀侵入到环空钻井液中，单次放水量不超过环空钻井液量的10%，多次放出盐水，降低高压盐水层的地层压力系数。解决了库车山前超深超高压盐水层安全钻井难题。现场试验表明，采取合理的控压排水方法能够降低盐水层的压力，在溢流与井漏的矛盾中找到压力平衡点，有利于井控安全的井筒状态。
2020, 37(6): 685-693.
doi: 10.3969/j.issn.1001-5620.2020.06.002
Abstract:
2016, 33(5): 1-8.
doi: 10.3969/j.issn.1001-5620.2016.05.001
Abstract:
2016, 33(6): 1-9.
doi: 10.3969/j.issn.1001-5620.2016.06.001
Abstract:
2017, 34(1): 1-8.
doi: 10.3969/j.issn.1001-5620.2017.01.001
Abstract:
2016, 33(6): 45-50.
doi: 10.3969/j.issn.1001-5620.2016.06.008
Abstract:
2018, 35(1): 101-104.
doi: 10.3969/j.issn.1001-5620.2018.01.019
Abstract:
2016, 33(1): 6-10.
doi: 10.3969/j.issn.1001-5620.2016.01.002
Abstract:
2018, 35(1): 34-37.
doi: 10.3969/j.issn.1001-5620.2018.01.006
Abstract:
2017, 34(1): 16-22.
doi: 10.3969/j.issn.1001-5620.2017.01.003
Abstract:
2018, 35(1): 71-76.
doi: 10.3969/j.issn.1001-5620.2018.01.014
Abstract:
Governed by：
China National Petroleum Corporation Ltd
China National Petroleum Corporation Ltd
Sponsored by：
CNPC Bohai Drilling Engineering Co. LtdPetroChina Huabei Oilfield Company
CNPC Bohai Drilling Engineering Co. LtdPetroChina Huabei Oilfield Company
Editor-in-Chief：Shi-chun Chen
Address：
Editorial Office of Drilling Fluid and Completion Fluid, Bohai Drilling Engineering Institute, Yanshan South Road, Renqiu City, Hebei Province
Editorial Office of Drilling Fluid and Completion Fluid, Bohai Drilling Engineering Institute, Yanshan South Road, Renqiu City, Hebei Province
Postcode： 062552
Tel：（0317）2725487 2722354
E-mail： zjyywjy@126.com
CN 13-1118/TE
ISSN 1001-5620
