复合有机树脂胶固堵漏液Ⅱ型机理研究

Study on Mechanism of Composite Organic Resin Cementing Plugging Fluid TypeⅡ

2020年长庆区域漏失井114口,其中水平井漏失60口,占漏失总数的52.6%,失返性漏失比例高达55.3%。堵漏损失总时间11990 h,其中水平井5840 h,堵漏材料损失总费用4895万元,其中水平井2702万元。陇东致密油、页岩油延长组水平段存在多个断层,形成垂直方向的裂缝,因重力压差和“假性闭合”双重因素的作用,造成堵漏浆在上井壁裂缝中无法有效滞留,挤封后返吐现象严重,导致堵漏成功率低、复发率高,其中华H50-7井累计堵漏7次,堵漏时间675 h,堵漏材料费362万元,漏失钻井液1650 m^(3)。文章针对水平段“断层”的垂直裂缝堵漏效果差、延长组“假性闭合”裂缝成功率低等难题开展了树脂胶固堵漏工作液的研发。

In 2020,there were 114 lost circulation wells in Changqing area,including 60 horizontal wells,accounting for 52.6%of the total loss,and the proportion of returnable loss was as high as 55.3%.The total time of plugging loss is 11990 h,including 5840 h for horizontal wells,and the total cost of plugging material loss is 48.95 million yuan,including 27.02 million yuan for horizontal wells.There are many faults in the horizontal section of Yanchang Formation of tight oil and shale oil in Longdong,forming vertical fractures.Due to the dual factors of gravity differential pressure and"false closure",the plugging slurry can not be effectively retained in the upper shaft wall fractures,and the backflow phenomenon is serious after squeezing,resulting in low plugging success rate and high recurrence rate.Among them,well Hua H50-7 has been blocked 7 times in total,with a plugging time of 675 h,the cost of plugging materials is 3.62 million yuan,and the lost drilling fluid is 1650 m^(3).Aiming at the problems of poor plugging effect of vertical fractures in horizontal section"fault"and low success rate of"false closure"fractures in Yanchang group,the resin cementing plugging working fluid was developed.