特低渗透油气资源在剩余油气资源中的地位越来越凸显。由于低孔低渗的特点,特低渗透油层在钻井、完井、采油、增产改造、EOR等全过程均会发生储层损害。以镇泾油田长8组为研究对象,对钻井完井液、压井液和压裂液顺序接触储层对储层的损害进行了方法探讨和实验评价。结果表明,钻井完井液对储层的损害最严重,压裂液次之,压井液最轻。分析表明,流体敏感性损害和漏失损害是钻完井液损害储层的主要因素。压裂液乳化、残渣、液相圈闭、浸泡时间损害,天然裂缝与水力裂缝堵塞,压裂液的冷却效应是压裂液损害的主要因素。最终提出了加入封堵剂改善钻完井液性能,从压裂工艺、压裂液体系出发改善压裂液的解决方式,实现全过程储层保护是特低渗油藏开发的关键。
The low permeability oil and gas resources in the residual resources are more and more important. Because of the characteristics of low permeability and low porosity in low permeability reservoir, the formation damage will happen in drilling and completion, production, production stimulation and EOR. This paper discusses the experimental method of damage evaluation of the drilling/completion fluid, kill fluid and fracturing fluid when successively contact reservoir in the Chang- 8 formation. The experimental results show that drilling/completion fluids is the most serious damage to the reservoir than fracturing fluid, and kill fluid is the lightest. Analysis shows that the fluid damage and loss are the main factors of damage to drilling and completing. Emulsification, residues, liquid trap, soaking time; natural fractures and hydraulic fracture blockage; the cooling effect of fracturing fluid are the main factors of fracturing fluid damage. The paper puts forward the suggestion to improve drilling fluid with sealing agent, improves the fracturing techniques and fracturing fluid to provide basic parameters for the systems formation damage control engineering.