川渝油气田完井液、压井液体系的应用技术

针对川渝油气田砂岩和碳酸盐岩储层渗透率差异大,黏土或泥页岩易发生水化膨胀,深井、高温、高矿化度、异常高压或高含H2S;CO2酸性气藏等因素的多变性难题,结合HSE的要求,提出了特定地层井况对完井修井作业的建议:①根据特定地层井况对完井修井作业进行专门的完井液、压井液方案设计;②研制新型高效的增黏剂、降失水剂、增效剂、温度稳定剂、防垢剂、除硫剂和缓蚀剂等添加剂来满足不同油气地层条件的需要;③选用可生物降解性好、低毒性的材料来提升完井液、压井液的环保功能;④通过优化完井液压井液体系配方技术和集成化技术的系统研究,以满足川渝油气田不同储集层条件的油气井完井与修井等安全作业以及HSE的要求。

Application of completion and killing fluid systems in Sichuan and Chongqing oil and gas fields

When wells were drilled in Sichuan and Chongqing oil and gas fields, various problems were encountered such as a big difference in the permeability between sandstone and carbonate reservoirs, hydration swelling which easily occurred in clay and shale formations, sour gas reservoirs with high temperature, abnormal high pressure, and a high content of H2S and CO2, and deep wells with high temperature and high salinity. Therefore, according to the requirement of HSE management, some technical measures were taken for completion and workover work under different well conditions at specific strata. First, a specific scheme for completion and killing fluid system was designed. Second, new additives with a high performance were developed including thickener, viscosity increaser, synergist, fluid loss additive, inorganic salt crystalline inhibitor, temperature stabilizer, anti scaling agent, desulfurizing agent, and corrosion inhibitor. Third, materials with biological degradability and low toxicity were selected to improve the eco friendliness of completion and killing fluids. Finally, a systematic study was carried out to optimize the formulation and integrated technology in completion and killing fluid system. Field application has proved that these above mentioned measures help ensure the safe operation of completion and workover under different reservoir conditions in Sichuan and Chongqing oil and gas fields.