摘要
苏里格气田召51区块下古生界奥陶系马家沟组属于以碳酸盐岩为主夹蒸发岩的复杂岩性地层,是典型的"三低储层"。采用常规酸液体系存在酸蚀反应过快、酸蚀裂缝作用距离短、高低渗储层改造不均匀等问题,最终导致酸压改造效果不理想。因此,针对该问题,开发了一种新的表面活性剂自转向酸体系,该体系在90℃时残酸黏度超过150 mPa·s,在地层内遇油气自动破胶,返排液黏度低于5 mPa·s。该酸液体系在苏里格气田召51区块现场应用1口井,转向效果明显,试气产量6×10~4 m^3/d,较采用常规酸压的邻井试气产量平均增加2倍,并创下了区块内单井酸压产量最高记录。
In Zhao 51 block, Sulige gasfield, the Lower Paleozoic Ordovician Majiagou Formation is one with complicated lithologies dominated by carbonates interbedded with evaporites. It is a typical 'three-low'reservoir of low porosity, low permeability, and low pressure. Conventional acid system has the problems of overquick etching reaction, short operating range of fracture acidizing, and uneven improvement of high- and low-permeability reservoir, resulting in inefficient acid fracturing. So, a new system of surfactant self-diverting acid is developed. At 90℃, the viscosity of residual acid of this system is over 150 m Pa·s; gel breaking occurs automatically when acid encounters oil and gas in formation; and the viscosity of flowback fluid is less than 5 m Pa·s.The acid system was applied to a well in Zhao 51 block showing evident diverting effect. The gas testing production reached 6×10~4m^3/d, which increased 2 times compared with adjacent well just adopting conventional acid fracturing. That is the highest record of acid fracturing production of single well in this block.
出处
《天然气勘探与开发》
2016年第4期56-58,71,共4页
Natural Gas Exploration and Development
关键词
苏里格气田
召51区块
碳酸盐岩
酸压
自转向酸
Sulige gasfield
Zhao 51 block
carbonate rock
acid fracturing
self-diverting acid
application
