頁巖氣水平井固井技術難點與對策淺析

頁巖氣水平井固井技術難點與對策淺析

鐘文力，洪少青，呂聰，張大翔，尹璽

(中國石化西南石油工程有限公司固井分公司，四川德陽 618000)

摘要：有效封固頁巖產層，避免氣體竄漏和穩定氣井產量，是頁巖氣水平井固井的難題。在分析總結頁巖地層特征、鉆井施工條件及后期完井工藝特點的基礎上，指出頁巖氣水平井固井技術難點主要集中在井壁的穩定性較差、套管安全下入難度大、套管居中度不高、油基鉆井液驅替及界面清洗困難、頂替效率不高、后期大型壓裂對水泥石性能要求高等方面。針對這些難點，從有效通井、扶正器合理安放保證套管居中、高效前置液技術、采用塑性水泥漿體系等幾個方面提出了提高頁巖氣水平井固井質量的技術對策，為今后頁巖氣水平井固井提供借鑒。現場應用表明，該配套技術提高了水泥環的封固質量。

關鍵詞：油基鉆井液；頁巖氣；固井；塑性水泥漿

中圖分類號:TE256

作者簡介：第一鐘文力(1987年生)，男，碩士研究生，助理工程師，2012年畢業于中國地質大學(武漢)，從事固井技術研究工作。郵箱：290941494@qq.com。

Difficulties and Countermeasures for Shale Gas Horizontal Well Cementing

Zhong Wenli, Hong Shaoqing, Lv Cong, Zhang Daxiang, Yin Xi

(CementingCompanyofSinopecSouthwestOilfieldServiceCorporation,Deyang,Sichuan618000,China)

Abstract：Effective sealing of shale gas layer to avoid gas leakage and stabilized gas production is difficult for shale gas horizontal well cementing. Based on analyzing and summarizing shale formation features, drilling conditions and characteristics of well completion technology at late stage, it was point out that difficulties in shale gas horizontal well cementing concentrated in poor sidewall stability, great difficulty in safe casing running, lower centering degree of casing, difficult displacement of oil-based drilling fluid and hard boundary washing, lower replacing efficiency, and high requirement of large-scale fracturing on cement paste performance, etc. Technical solutions for enhancing shale gas horizontal well cementing quality were proposed in terms of effective drifting, rational placement of stabilizer to guarantee casing centralizing, efficient preflush technique, and use of plastic cement slurry. All these could be reference to shale gas horizontal well cementing in future. Field application showed that the new technology could enhance cementing quality of cement ring.

Key words: oil-based drilling fluid; shale gas; cementing; plastic cement slurry

頁巖氣是一種重要的非常規天然氣，在我國儲量和產能潛力巨大[1，2]。由于頁巖含泥質較多，具有易膨脹、易破碎，且儲層孔隙度和滲透率低的特點，其完井方式通常是套管固井后射孔完井，采用多級分段壓裂增產技術來提高頁巖氣氣井產量，因此對固井技術要求很高[3-9]。

與常規固井相比，頁巖氣井固井除水泥漿性能要求高外，還需要安全下入長水平段套管和提高套管居中度，采用有效手段驅替油基鉆井液及滿足后期壓裂要求。……