致密气藏二开结构水平井钻井液体系及现场应用  

The Field Application of a Drilling Fluid for a Two-Interval Horizontal Well Penetrating Tight Gas Reservoir

作　　者：孔维升 李晓明[1] 韩成福[1] 屈艳平[1] 王清臣[1] 赵鹏 KONG Weisheng;LI Xiaoming;HAN Chengfu;QU Yanping;WANG Qingchen;ZHAO Peng(CCDC Changqing General Drilling Company,Xían,Shaanxi 710018)

机构地区：[1]川庆钻探工程有限公司长庆钻井总公司,西安710018

出　　处：《钻井液与完井液》2023年第1期73-81,共9页Drilling Fluid & Completion Fluid

基　　金：国家自然科学基金项目面上项目“基于扰动状态理论的井壁失稳综合分析与计算模拟”(51974255);国家自然科学基金项目面上项目“致密砂岩油藏复杂壁面裂缝内支撑剂耦合运移铺置行为研究”(51874240);陕西省自然科学基础研究面上项目“基于损伤流变效应的泥页岩井壁失稳机理研究”(2020JM-544)。

摘　　要：为解决苏里格气田致密气藏二开结构水平井钻井施工中地层塌漏矛盾突出、降摩减阻及井眼净化困难等技术难题,基于地质特性和泥岩坍塌机理分析,建立摩阻扭矩计算模型,对比变更井身结构摩阻及扭矩变化规律。通过室内研究筛选采用纳米乳液、软硬结合的封堵剂、多元复配的润滑剂和高效提切剂,研发出新型强封堵超润滑水基钻井液体系。室内研究显示,该钻井液体系具有强抑制性和封堵防塌性,能够有效延长硬脆性泥岩失稳周期,进而深度维持井壁稳定,同时也具备良好的流变性和润滑性,且含砂和固相含量低,降摩减阻效果显著。现场应用表明,应用该钻井液体系后下套管摩阻控制在350 kN以内,钻进下放摩阻降低24.21%,扭矩降低34.31%,平均钻井周期为29.04 d,平均机械钻速为17.64 m/h,较三开结构水平井提速36.5%,井塌划眼损失时间降低89.50%,为苏里格气田致密气藏二开结构水平井推广应用提供了有力保障。Two-interval horizontal well profile is used to develop the tight gas reservoirs in the Sulige gas field.Downhole problems such as coexistence of borehole wall collapse and mud losses,high friction and poor hole cleaning have long remained difficulties during drilling operations.Based on the analyses of the geological characteristics and the collapse mechanisms of shale formations,a model for friction and torque calculation is developed.The changes of friction and torque between different well profiles are compared.A new drilling fluid with good plugging capacity and lubricity was developed with a nanophase emulsion,plugging agents o hard and soft particles,compound lubricants and high efficiency gel strength additives which were all selected through laboratory experiment.This drilling fluid has been successfully applied in field operations.Laboratory study has shown that this drilling fluid has good inhibitive capacity and good plugging capacity,and it can extend the instability period of hard and brittle shales,thereby maintaining the borehole wall stable.This drilling fluid also has good rheology and lubricity,low sand content and solid content.In field application,the resistance to casing string running into the hole was controlled within 350 kN,the friction to drilling string running into the hole was reduced by 24.21%,the torque was reduced by 34.31%,the average drilling time was 29.04 d,the average ROP was 17.64 m/h,which was 36.5%higher than that in drilling three-interval horizontal wells.Time spent in reaming because of borehole collapse was reduced by 89.50%.This drilling fluid has provided a powerful technical support for promoting the application of two-interval horizontal drilling in developing the tight gas reservoirs in the Sulige gas field.

关 键 词：致密气藏 二开结构水平井 钻井液体系 纳米乳液 降摩减阻 塌漏矛盾 

分 类 号：TE254.3[石油与天然气工程—油气井工程]