页岩地层纳微米封堵剂封堵性评价方法  

Study on Methods of Evaluating Plugging Capacity of Nanometer and Micrometer Sized Plugging Agents for Shale Formations

作　　者：代锋 易刚 张婧 王睿 吴申堯 黄维安[3] DAI Feng;YI Gang;ZHANG Jing;WANG Rui;WU Shenyao;HUANG Weian(Petroleum Engineering School,Southwest Petroleum University,Chengdu,Sichuan 610500;Sichuan Changning Natural Gas Development Co.,Ltd,Chengdu,Sichuan 610000;School of Petroleum Engineering,China University of Petroleum(East China),Qingdao,Shandong 266580)

机构地区：[1]西南石油大学石油与天然气工程学院,成都610500 [2]四川长宁天然气开发有限责任公司,成都610000 [3]中国石油大学(华东)石油工程学院,山东青岛266580

出　　处：《钻井液与完井液》2023年第6期733-741,共9页Drilling Fluid & Completion Fluid

基　　金：四川长宁天然气开发有限责任公司重点科技攻关项目“纳微米封堵剂评价方法及作用机理研究”(20210604-12)。

摘　　要：纳微米封堵剂种类虽然较多,目前的评价方法从纳微米尺度评价封堵剂性能的准确性和有效性不足,且没有统一的标准。针对纳微米封堵剂的评价方法问题,选用了纳米孔膜和致密砂床作为介质模拟页岩地层微裂隙,以滤失量和砂床湿润深度作为指标来评价纳微米封堵剂的封堵性能。纳米孔膜法使用100~450 nm孔径的滤膜,平行实验数据拟合线波动很小,适用于评价35~450 nm的纳微米封堵剂;致密砂床法使用200目石英砂填充,多组实验数据方差值为0.2131、平行性好,适用于评价24.6~500μm的纳微米封堵剂。采用该方法对3种粒径差别较大的封堵剂超细碳酸钙、乳化改性橡胶MORLF、ULIA纳米承压封堵剂进行了评价,优选出具有形变性的乳化改性橡胶MORLF为最优纳米封堵剂。建立方法和优选出的纳米封堵剂在长宁区块现场应用7口井,与同区块采用常规油基钻井液的其他已完钻井相比,复杂地层的井径扩大率平均降低12.74%、建井周期平均缩短12 d,进一步证实评价方法具有平行性和准确性。Methods presently in use for evaluating the performance of many kinds of plugging agents in nanometer and micrometer levels still lack the required accuracy and effectiveness,and no commonly followed standards are available.To deal with these problems,a mesoporous membrane and a dense sand-bed are selected as the media to simulate the microfractures in shale formations,and the filtration rate and the wetted depth of the sand-bed are used as the indices for evaluating the performance of a nanometer or micrometer plugging agents.The mesoporous membrane method uses a filter membrane with pore sizes between 100 nm and 450 nm,the fitting lines of the parallel experimental data have minimal fluctuations,and this method is thus suitable for evaluating the performance of the plugging agents with particle sizes distributed between 35 nm and 450 nm.The dense sand-bed method uses 200-mesh quartz sands as the packing material,and the variance of several experimental data is 0.2131,meaning that the parallelism of the experiments is good.This method is suitable for evaluating plugging agents with particle sizes distributed between 500 nm and 24.6μm.Using this method,three ultra-fine plugging agents with big differences in particle sizes,which are ultra-fine calcium carbonate,emulsified rubber MORLF and ULIA,were evaluated for their performance,and the MORLF with deformability,was finally selected as the most suitable nanometer plugging agent.The evaluation methods presented and the nanometer-sized plugging agents have been applied on 7 wells drilled in the Changning block.Compared with other wells drilled with conventional oil based drilling fluids,the average percent hole washout of the 7 wells is reduced by 12.74%,and average drilling time reduced by 12 d,further proving that the methods presented have good parallelism and high accuracy.

关 键 词：页岩地层 纳微米封堵剂 纳米孔膜法 致密砂床法 井壁稳定 

分 类 号：TE254.1[石油与天然气工程—油气井工程]