Synthesis and Evaluation of High Temperature Water Base Drilling Fluid Filter Loss Reducer

Malfunction of filter loss reducer at elevated temperatures and high salinity environments are difficult problems encountered in deep and ultra-deep well drilling.A high temperature water base drilling fluid filter loss reducer,JLS²⁰⁰,has been developed using acryl amide,2-acrylamide-2-methyl propane sulfonic acid,N-Vinyl pyrrolidone and N-isopropyl acrylamide as raw materials.JLS²⁰⁰,as indicated by laboratory evaluation,can be used at 200℃,or in saturated saltwater drilling fluids,without losing its filtration control capacity.KCl drilling fluids treated with JLS²⁰⁰ have low filtration rate and good rheology,the API filtration rate has been reduced from 12 mL to 3.2 mL after treatment of the fluids with 1% JLS²⁰⁰ and ageing at 200℃,while the HTHP filtration rate reduced from 54 mL to 15 mL.The viscosity and gel strengths do not change remarkably before and after the treatment.JLS²⁰⁰ as a high performance filter loss reducer will find its application in deep and ultra-deep well drilling.