泡沫随钻堵漏钻井液体系

针对冷家油田老区块胶结差、破碎地层的井漏问题,通过分析井漏原因,制定解决对策,优选出泡沫聚合物钻井液体系和高效随钻堵漏剂CLPA-1。通过室内实验,选择XC与CMC按1∶2的比例复配作增黏剂,SMP-1、SAS、CMS按0.75∶0.5∶1的比例复配作降滤失剂,发泡剂和稳泡剂的浓度约为0.025%。CLPA-1是一种由预交联凝胶颗粒、吸水性树脂和高分子聚合物为基本材料合成的随钻堵漏剂,其瞬时滤失量小,在加量为3%时堵漏效果好,承压达到5 MPa;为提高滤饼承压能力,体系还加入了2%超细碳酸钙。介绍了该体系在冷42-41-164CH和洼60-H2302井的成功应用情况;在该油田其他相同区块易漏层应用的8口井,提前防漏效果显著,预防井漏发生4口井,井漏后一次堵漏成功3口井,且堵漏后再钻无漏失情况,堵漏成功率大于80%。该微泡沫低固相聚合物体系和随钻堵漏剂CLPA-1,利用密度控制技术,能解决亏空、胶结性差、存在微裂缝的老区块二次开发中产生的井漏难题。

Study and Application of Foam LCM Drilling Fluid

A high performance foam LCM mud, CLPA-1, was developed for use in the Block Lengjia where lost circulation posed difficulties to drilling the old, fractured formations. Lost circulation did not occur in four wells in this area drilled with CLPA-1, and in another three wells lost circulations were stopped first time when they occurred, with no subsequent lost circulation happened. Field application proved that the CLPA-1 foam mud was effective in lost circulation control in the area, where mud losses into fractured formations had long been common.