Resource Utilization of Pyrolyzed Oil Cuttings (Ⅱ): Study on the Performance of Cement Slurry with Drilled Cuttings Residue

Residues from pyrolyzed drilled cuttings from wells drilled with oil base muds are tried to replace part of the oil well cement (YJ) to make cement slurry for well cementing. Studies have been conducted on the effects of the concentration of pyrolyzed oil drilled cuttings (PODC) and water/solid ratio on the properties of cement slurry. The PODC was measured for its early heat of hydration, hydration products of set cement, pore structure and microscopic morphology with ICC, XRD, MIP and SEM, respectively. The PODC was optimized for its engineering performance with filter loss reducer CHL, silica fume and crystal expansion agent KW-4. It was found that with an increase in the concentration of PODC, the mobility of the cement slurry was increased, the density of the cement slurry was reduced, the setting time of the cement slurry was prolonged, and the compressive strength of the set cement was reduced to some extent. At water/solid ratio of 0.40, a cement slurry with drilled cuttings residue for intermediate casing cementing, PODC-6:40% YJ + 60% PODC + 3% CHL + 4% silica fume + 2% KW-4, and a cement slurry with drilled cuttings residue for production casing (nonproductive section) cementing, PODC-3:70% YJ + 30% PODC + 3% CHL + 3% silica fume + 2% KW-4, were formulated respectively. The engineering properties of the cement slurries with drilled cuttings residue have satisfied the needs of well cementing operations. Microscopic analyses of the cement slurries indicated that cement slurries with PODC had low heat of hydration, and the hydration products of the cement slurries were C-S-H gel and CH. Compared with cement slurry not treated with PODC, the PODC cement slurries had less hydration products, and the degree of density of the PODC cement slurries was also slightly reduced. It is expected that this study will provide a new approach to resource utilization of PODC, and is of potential environmental benefit and economic benefit.