深水恒流变无固相储层钻井液的制备与性能评价

Preparation and Performance Evaluation of Solid-free Constant Rheological Drilling Fluid with Reservoir Protection for Deep-water Drilling

在深水油气田钻井过程中,由于海底泥线附近的温度较低,易导致钻井液出现增稠、糊塞和跑浆等问题。针对该问题,以丙烯酰胺、N-乙烯基己内酰胺、二乙烯苯、烯丙基磺酸钠等为原料制备温敏增稠共聚物(ASSN),再与香豆胶复配制得具有低温恒流变特性的流型调节剂。将流型调节剂与其他处理剂混合制得深水恒流变无固相储层钻井液。评价了ASSN、流型调节剂和钻井液的性能。结果表明,ASSN溶液的临界缔合温度为27℃。以0.5%ASSN和0.3%香豆胶作为流型调节剂,其水溶液的黏度在4~60℃较为稳定。流型调节剂对钻井液在低温下的流变性起到了良好的调控作用。加重剂对钻井液低温调控能力的影响较小。流型调节剂与钻井液其他处理剂的配伍性良好。钻井液具有良好的抗侵污性能、抑制性能、润滑性能和储层保护性能,满足现场钻井需求。

In the drilling process of deep-water oil and gas fields,due to the low temperature near the bottom mud line,it is easy to appear thickening,plugging and slurry running of drilling fluid.In order to solve the problem,the thermosensitive thickening copolymer(ASSN)was prepared from acrylamide,N-vinyl caprolactam,divinylbenzene and sodium allyl sulfonate.Then the flow pattern regulator with constant rheological properties at low temperature was prepared by mixing ASSN with fenugreek gum.The solid-free constant rheological drilling fluid with reservoir protection for deep-water drilling was prepared by mixing flow pattern regulator with other treatment agents.The performance of ASSN,flow pattern regulator and drilling fluid was evaluated.The results showed that the critical association temperature of ASSN solution was 27℃.When 0.5%ASSN and 0.3%fenugreek gum were used as flow pattern regulators,the viscosity of the aqueous solution was stable in the range of 4—60℃.The flow pattern regulator played a good role in regulating the rheology of drilling fluid at low temperature.The weighting agent had little effect on the control ability of drilling fluid at low temperature.The flow pattern regulator had good compatibility with other treating agents of drilling fluid.The drilling fluid had good anti-fouling performance,inhibition performance,lubrication performance and reservoir protection performance,which could meet the requirements of field drilling.