【摘要】 为了解决海上水力加砂压裂增产措施受限、片麻岩基质酸化增产潜力有限和防砂完井方式带来的难题,基于海上大型整装太古界潜山片麻岩A凝析油气藏埋藏深、超高温异常高压、特高含凝析油、地露压差小、储层非均质性强、岩性复杂等特征,开展了缝网酸压地质和工程可行性系统研究,剖析了储层酸压改造难点及挑战,提出了复杂缝网酸压技术的实现途径,并研制出气湿反转剂、过筛管液体暂堵剂、低伤害缝网酸液体系。研究结果表明:(1)纳米气湿反转剂协同多氢螯合酸可有效刻蚀形成高导流缝网,并改变岩石润湿性,提高气相相对渗透率;(2)液体暂堵剂依靠相态转化实现暂堵和自清洁功效,能顺利通过筛管等防砂完井工具;(3)通过工艺参数优化设计,对海上A凝析油气藏H1井开展缝网酸压技术现场实践,泵注总液量489.8 m~3,措施后单井产气量较改造前提升48%,凝析油产量提升11%,效果显著。结论认为,所研发的液体暂堵剂实现暂堵转向,优化了片麻岩缝网酸压改造用酸液体系和工艺参数,为海上超高温裂缝性片麻岩凝析油气藏高效开发提供了有效技术支撑,同时也为其他地区同类油气藏增产改造提供了借鉴。更多还原

【Abstract】 In order to solve the problems caused by restricted application of offshore hydraulic sand fracturing measures,limited stimulation potential of gneiss matrix acidizing and sand control completion mode,this paper systematically studies the geological and engineering feasibility of fracture-network acid fracturing and analyzes the difficulties and challenges in acid fracturing stimulation based on the characteristics of offshore large-scale monoblock Archean buried hill gneiss condensate reservoir A in terms of great burial depth,ultra-high temperature,abnormal pressure,ultra-high condensate content,small difference between formation pressure and dew point pressure,strong reservoir heterogeneity and complex lithology.Then,the realization way of acid fracturing with complex fracture networks is put forward.Finally,gas-wetting reversal agent,through-screen liquid temporary plugging agent and fracture-network acid system with low damage are developed.And the following research results are obtained.First,nano gas-wetting reversal agent collaborating with multi-hydrogen chelating acid can realize effective etching to form high-conductivity fracture networks and change rock wettability,so as to improve the relative permeability of gas phase.Second,liquid temporary plugging agent can achieve a temporary plugging and self-cleaning effect by means of phase transformation and can smoothly run through sand control completion tools,such as screen pipe.Third,based on the optimized design of process parameters,the fracture-network acid fracturing technology is practically applied to Well H1 in offshore condensate reservoir A.The injected liquid volume is totally 489.8 m~3.After the application of the measure,the single-well gas production rate is 48%higher than the initial value and the condensate production rate is 11%higher,indicating a remarkable application effect.In conclusion,the developed liquid temporary plugging agent realizes temporary plugging and diversion,and the acid system and process parameters for the fracture-network acid fracturing of gneiss are optimized,which provides an effective technical support for the efficient development of offshore ultra-high temperature fractured gneiss condensate reservoirs and the reference for the stimulation of similar oil and gas reservoirs in the other areas.更多还原