页岩油气井筒全生命周期完整性技术研究进展  

Research Progress on Shale Oil and Gas Well Integrity Technology

作　　者：杨尚谕 闫炎 韩礼红 曹婧 牟易升 YANG Shangyu;YAN Yan;HAN Lihong;CAO Jing;MOU Yisheng(State Key Laboratory of Oil and Gas Equipment,CNPC Tubular Goods Research Institute,Xi′an,Shaanxi 710077,China)

机构地区：[1]中国石油集团工程材料研究院有限公司,油气钻采输送装备全国重点实验室,陕西西安710077

出　　处：《石油管材与仪器》2024年第3期1-6,I0003,I0004,共8页Petroleum Tubular Goods & Instruments

基　　金：黑龙江省“揭榜挂帅”科技攻关项目“古龙页岩油增产改造关键技术研究”(编号:2021ZZ10-04);中国博士后科学基金资助项目“地层滑移条件下空心水泥对套管变形的缓解机理与套变程度可控性研究”(编号:2023M743886);陕西省博士后科学基金资助项目“射孔过程水泥环完整性失效机理与失封范围表征方法”(编号:2023BSHGZZHQYXMZZ50)。

摘　　要：综述了国内外页岩油气开发全生命周期井筒完整性失效的概况。明确了失效形式分为两大类,一是结构完整性失效,即套管产生变形;二是密封完整性失效,即出现环空带压现象。总体来看,我国的页岩气井筒完整性失效问题明显比国外严重,其中套管变形问题严重制约了我国页岩气的高效开发。分析了页岩气井筒完整性失效机理,包括压裂前的下套管、注水泥、水泥候凝、分段压裂等多个阶段。分析表明,复杂的地应力条件、地层各向异性、长水平段非均质性、岩性界面、断层和裂缝发育、井眼轨迹质量差、下套管困难等对压裂前套管的原始应力有明显影响。在压裂过程中,套管承受拉压交变载荷、近井地应力场及地层性质动态变化、裂缝非均匀扩展、微断层滑移、套管温度的急剧变化、水泥环出现微环隙或微裂隙等是导致井筒完整性失效的原因。对中国页岩气井套管变形问题而言,以地层滑移的影响最为显著。最后提出了井筒完整性控制方法,包括:井眼轨道优化与轨迹控制、套管钢级与壁厚优选、固井方式优化、水泥浆体系优化、分段分簇及压裂参数优化等,可为我国页岩气井筒完整性失效问题的治理提供参考。The general situation of wellbore integrity failure during the whole life cycle of shale oil and gas development at home and abroad is reviewed.The failure forms are classified into two categories:one is structural integrity failure,that is,casing deformation.The second is the failure of seal integrity,that is,the phenomenon of annular pressure.On the whole,the problem of shale gas wellbore integrity failure in China is obviously more serious than that in foreign countries,especially the casing deformation has been restricted the efficient development of shale gas in China.The failure mechanism of shale gas wellbore integrity is analyzed,including in phases of casing,cementing,cement waiting and stage fracturing.The results show that complex ground stress conditions,formation anisotropy,long horizontal anisotropy,lithologic interface,fault and fracture development,poor quality of borehole track and difficulty in casing running have obvious effects on the original casing stress before fracturing.In the fracturing process,the casing is subjected to tension and compression alternating loads,the near-wellbore stress field and the dynamic change of formation properties,the fracture non-uniform expansion,micro-fault slip,the sharp change of casing temperature,and the micro-annulus or micro-crack in the cement sheath are the causes of wellbore integrity failure.For shale gas casing deformation in China,formation slip is the most significant influence factor.Finally,the wellbore integrity control methods are proposed,including well track optimization and trajectory control,casing steel grade and wall thickness optimization,cementing optimization,cement slurry system optimization,segmentation clustering and fracturing parameter optimization,etc.,which can provide reference for the treatment of shale gas wellbore integrity failure in China.

关 键 词：页岩油气 井筒完整性 下套管 固井 多级压裂 

分 类 号：TE931[石油与天然气工程—石油机械设备]