高含长石低孔低渗砂岩油藏酸压体系及工艺优化  

Acid Fracturing System and Technology Optimization for Sandstone Reservoir with High Content of Feldspar and Low Porosity and Low Permeability

作　　者：李君权[1] 鬲新鹏 

机构地区：[1]延长油田股份有限公司黄陵勘探开发项目指挥部,陕西延安727300

出　　处：《中外能源》2016年第8期51-58,共8页Sino-Global Energy

摘　　要：黄陵储层延长组长6、长8油藏属于典型低温低压高含长石低孔低渗砂岩油藏,储层改造中需充分考虑构造特征、岩性组成、孔渗性质、温压条件、岩石力学特征和潜在损害因素等,掌握该类储层改造和酸压工艺的影响机理,室内实验优化出一套适用于该储层的前置酸和压裂液体系和前置酸多级加砂压裂配套工艺流程,并进行了软件模拟和现场施工。结果表明,前置酸体系具有溶蚀能力强、损害程度低、水化性能好、易反排、低残渣等优点,易于溶蚀砂岩储层孔隙喉道中的填隙物,且不损害长石骨架结构。压裂液体系配方为0.25%胍胶+0.4%助排剂+0.1%AE1910活性剂+0.3%黏土稳定剂+交联剂0.8%硼砂BS+0.8%APS,满足储层特性和携砂需求。前置酸多级加砂压裂工艺以加砂量20~40m^3,排量1.8~2.0m^3/min,平均砂液比25%~35%,前置液量占总液量比例15%~20%进行施工。该工艺在延长组长6油层探井应用后,单井日产油3.5m3/d,实现了工业油流目标。Chang 6 and Chang 8 oil reservoirs in Yanchang formation of Huangling reservoir belong to the rep-resentative low-temperature,low-pressure and low-porosity and permeability sandstone reservoirs with high content of feldspar.During reservoir stimulation,the structure characteristics,lithological composition,porosity and permeability characteristics,temperature and pressure condition,rock mechanics characteristics and potential damage factors and so on should be considered.Influence mechanisms of stimulation and acid fracturing process in such reservoir should be mastered.A set of acidic preflush,fracturing fluid system and matching process of acidic preflush and multi-stage sand fracturing suitable for this reservoir was optimized in the laboratory ex periment,and it was simulated by software and was applied in the field.The results show that the acidic preflush system has strong dissolution ability,low damage degree,good hydration performance,being easy to flow back,less residue and other advantages,which is easy to dissolve the interstitial material in pores and throats of the sandstone reservoir with no harm to feldspar framework structure.The formula of the fracturing fluid system was 0. 25 % guanidine gum ＋ 0. 4 % clean- up additive ＋ 0. 1 % AE1910 surfactant ＋ 0. 3 % clay stabilizer ＋ crosslinking agent 0.8% borax BS ＋0.8% APS,which met the demands of reservoir characteristics and sand carrying.The acidic preflush and multi-stage sand fracturing process was applied as sand of 20-40m^3,displacement of 1.8-2.0m^3/min,average sand fluid ratio of 25%-35%,and preflush volume accounts for 15%-20% total amount of liquid.After the application of the optimized technology in exploration wells of Chang 6 oil reservoirs in Yan-chang formation,daily oil output per well was 3.5m^3/d,and the goal of commercial oil flow was achieved.

关 键 词：高含长石 低孔低渗砂岩油藏 前置酸体系 多级加砂 压裂工艺 

分 类 号：TE357.2[石油与天然气工程—油气田开发工程]