A Novel Compound Lost Circulation Material FM Super Gel

A new FM super gel was studied for its performance and mechanism as a lost circulation material.As an LCM made from polymers that swell when water is absorbed in, and some rigid matrix materials, FM super gel retains its function at temperatures up to 140℃.The FM super gel can swell when mixed with water, thus seals channels through which mud is lost.In the studies, quartz sands(particle sizes 0.3-2.0 mm), steel balls(diameters 4.3-7.8 mm) and slat(with slits of 1.0-5.0 mm) were used to simulate fractured formations with high permeability and large pore throats.The FM super gel stopped mud losses on the three simulators when total mud losses were 86-113 mL, 204-382 mL and 22-64 mL, respectively, and the maximum pressure exerted on the FM super gel was7.0 MPa.When rigid particles, elastic particles, fibers and deformable fills were added to the FM super gel, the total volumes of mud losses through the steel balls and the slat were reduced to 63-95 mL and 15-43 mL, respectively, and the maximum pressure exerted on the FM super gel was increased to 9.0 MPa, indicating that the pressure containment was enhanced.The FM super gel was used in the well Nanpu-13-1170 and the well Daji-4-9-Xiang-4, and had gained great success in mud loss control, with no reoccurrence of mud losses.