SP储气库应用PERFECTDRILL盐水体系钻井液的实践与认识

Practice and understanding of PERFECTDRILL brine-based drilling fluid in SP gas storage

SP储气库前期部署两口水平井,为满足储气库优质钻井和储层保护的需求,开展了PERFECTDRILL盐水钻井液体系优化试验研究。通过开展室内实验优化钻井液配方,结合现场实际情况有针对性地调整钻井液配方,探索盐水钻井液在SP储气库钻井应用中的适用性,为SP储气库两口水平井提供二开、三开钻井液技术保障。SPKP1井三开完钻井深4019m,三开钻井周期比设计钻井周期提前54天,电测井径平均扩大率为2.2%。SP-KP2井三开完钻井深3963m,三开钻井周期比设计钻井周期提前34天,电测井径平均扩大率为5.7%。PERFECTDRILL盐水钻井液体系能够满足长裸眼段钻井施工要求,为泥岩提供较好的抑制性,在实现储层保护的前提下能够保持井眼的润滑性及稳定性,有效提高机械钻速,施工过程中未出现井壁失稳、脱压、卡钻等井下复杂情况。

Two horizontal wells were deployed at the early stage for SP gas storage.In order to meet the requirements of high-quality drilling and reservoir protection,test and research on PERFECTDRILL brine-based drilling fluid system have been optimized.Through laboratory experiments,the drilling fluid formula was optimized,and which could be adjusted at site combined with the actual situation.The applicability of brine-based drilling fluid in SP gas storage was explored,which provided technical support for two horizontal wells in second and third drilling operation in SP gas storage.The third times of drilling depth of the well SP-KP1 is 4019 m,whose drilling cycle of well SP-KP1 is 54 days ahead of the designed drilling cycle,and the average enlargement rate of electric logging hole size is 2.2%.The third times of drilling depth of the well SP-KP2 is 3963 m,whose drilling cycle is 34 days earlier than the designed drilling cycle,and the average enlargement rate of electric logging hole size is 5.7%.PERFECTDRILL brine-based drilling fluid can meet the drilling operation requirements at long open hole section,which provides good inhibition for mudstone,maintain the lubricity and stability of borehole under the premise of reservoir protection,effectively improve the ROP.There were no downhole complex situations happened such as wellbore instability,WOB reduction and bit sticking during the drilling operation.