四川盆地威远区块页岩气水平井固井技术浅析

发布时间：2018-10-29 21:51

【摘要】：针对威远区块页岩气水平井水平段长、套管居中度不高、油基钻井液与水泥浆兼容性差、驱替顶替效率不高、后期大型压裂易造成环空窜气等难点,通过合理安放扶正器保证套管居中、优化前置液技术、采用塑性水泥浆体系等几个方面提出了技术对策。下套管前认真通井,清洁净化井眼,采用套管"抬头"技术,斜井段以下采用旋流刚性扶正器和整体式弹性扶正器交叉使用的方式,可以保证套管居中度在72%以上。冲刷隔离液削弱油膜的结构力和内聚力,达到较好冲刷效果;具有一定黏度的加重隔离液有效隔开油基钻井液和水泥浆。通过加入特制塑性剂材料提高水泥石形变能力,达到固井及压裂的要求。现场应用表明,该技术提高了水泥环的封固质量,为今后该地区页岩气水平井固井提供了技术支撑。
[Abstract]:In view of the difficulties such as long horizontal section of shale gas horizontal well in Weiyuan block, low casing centrality, poor compatibility between oil base drilling fluid and cement slurry, low displacement efficiency, and large fracturing in late stage, it is easy to cause annular gas channeling. Several technical countermeasures are put forward through reasonably placing centralizer to ensure casing being in the center, optimizing the technology of front liquid and adopting plastic cement slurry system. In order to ensure the casing centrality above 72%, it is necessary to use the technology of "rising up" of casing before casing down-casing, and cross use of swirl rigid centralizer and integral elastic centralizer below the inclined well. The flushing isolating fluid weakens the structure and cohesion of the oil film and achieves better scouring effect, and the oil base drilling fluid and cement slurry are effectively separated by the enhanced isolating fluid with a certain viscosity. The deformation ability of cement stone was improved by adding special plastic agent to meet the requirements of cementing and fracturing. The field application shows that this technology improves the cementing quality of cement ring and provides technical support for the cementing of shale gas horizontal wells in this area in the future.
【作者单位】：中国石化西南石油工程有限公司固井分公司;
【分类号】：TE256

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