塔中碎屑岩井自愈合水泥浆固井技术  

Cementing Wells Penetrating Clastic Rocks with Self-healing Cement in Block Tazhong

作　　者：田宝振 李清洁 覃毅 孙万兴 沈磊 陈大沧 张亮 周坚 

机构地区：[1]渤海钻探工程有限公司第一固井分公司,河北任丘062552

出　　处：《钻井液与完井液》2016年第6期84-90,共7页Drilling Fluid & Completion Fluid

基　　金：中国石油集团渤海钻探工程有限公司局级项目"塔里木台盆区碎屑岩固井技术研究与试验"(2015ZD12Y-2)部分研究成果

摘　　要：塔里木油田塔中区块碎屑岩地层结构复杂、成岩性差、韧性小、脆性高,钻井施工过程中井壁易垮塌、剥落,导致形成"大肚子"、"糖葫芦"等不规则井眼;生产套管固井存在二叠系承压能力较低、易漏,地层油水同层、砂泥互层、砂层薄含油层多、油层水层相隔很近,油水互窜,难压稳,固井质量要求高等难点。针对这些难点,通过水泥浆气窜机理研究,采用硅粉、减轻增强材料BCE-610S、中温缓凝剂BXR-200L、减阻剂BCD-210L、自愈合剂BCY-200S、防窜降失水剂BCG-200L,研究出了密度为1.35 g/cm^3的领浆与密度1.88 g/cm^3的尾浆。该水泥浆体系具有稳定性好、流动性好、零析水,失水量低(小于50 m L)、弹性模量接近于7 GPa,抗压强度高,防窜能力强等特点。同时优化水泥浆柱结构实现平衡压力固井,应用固井软件模拟提高顶替效率,形成了一套适合塔中碎屑岩井固井的自愈合水泥浆固井技术。塔中4口井固井结果显示,4口井全井封固质量合格,主力油气层段封固优质,有效解决了塔里木碎屑岩固井施工难题。The clastic formations in the Block Tazhong have complex structures, poor lithological characters and toughness, and high brittleness. During drilling operation, wells penetrating the clastic formation have experienced borehole collapse and sloughing, and borehole of irregular sizes was formed. Cementing of the production casing string has long been facing with diffculties such as low formation pressure and mud losses in the Permian system, coexistence of oil and water in the same zone, interbedding of sandstone and shale, thin sandstones and hence multiple pay zones, short distance between a pay zone and a water zone, and inter-channeling of oil and water, etc. Based on the study on the mechanism of gas-channeling in cement slurry, a leading slurry with density of 1.35 g/cm3, and a tail slurry with density of 1.88 g/cm3 were formulated with several additives, such as silica powder, lightweight material BCE-610S, medium temperature retarder BXR-200L, drag reducer BCD-210L, self-healing agent BCY-200S and anti-channeling flter loss reducer BCG-200L. This cement slurry had good stability, mobility, zero free water, low fltration rate （flter loss〈50 mL）, elastic modulus near 7 GPa, high compressive strength, and ability of anti-channeling. By optimizing the composition of the cement slurry column in hole, pressure balancing during well cementing was realized. Using well cementing software, the displacing effciency was improved. As a set of self-healing cementing technology, it has been used in 4 wells in Tazhong, all cementing jobs successful, especially the main pay zones which were cemented with excellent job quality, effectively solved the diffculties in well cementing in clastic rock formations.

关 键 词：碎屑岩井 自愈合水泥浆 平衡压力固井 现场应用 

分 类 号：TE256[石油与天然气工程—油气井工程]