致密砂岩气藏水相圈闭损害评价方法研究

发布时间：2018-04-27 13:46

本文选题：致密砂岩 + 气藏　；参考：《西南石油大学》2015年硕士论文

【摘要】：致密砂岩气在天然气储量增长和能源供应方面发挥着越来越重要的作用,已成为非常规天然气勘探开发的重点领域。水相滞留诱发的水相圈闭损害是致密砂岩气藏最主要的损害类型之一。客观评价水相圈闭损害是有效防治水相圈闭损害的基础,而以往水相圈闭损害评价方法在致密砂岩气藏水相圈闭损害评价中存在针对性不强、所取得的研究成果应用受限等问题,亟待开展致密砂岩气藏水相圈闭损害评价方法研究。以鄂尔多斯盆地典型致密砂岩为研究对象,基于水相圈闭损害影响因素及过程机理,总结了致密砂岩气藏水相圈闭损害评价的控制因素,包括水相圈闭损害过程的不同作业形式、物性及孔隙结构、初始含水饱和度、气体滑脱效应和储层敏感性。基于所总结的水相圈闭损害评价的控制因素,分析了致密砂岩气藏水相圈闭损害评价中存在的问题。致密岩心可溶盐的清洗、初始含水饱和度的建立、气体滑脱效应的弱化、气藏压力的模拟、不同作业形式下水相圈闭损害过程的模拟及损害评价指标的确定均影响水相圈闭损害的客观评价。针对以上水相圈闭损害评价中存在的问题,形成了致密砂岩气藏水相圈闭损害评价方法。采用反复加压饱和法对致密岩心洗盐,采用毛管自吸法建立初始含水饱和度,在岩心出口端施加回压至界限压力弱化气体滑脱效应,对岩心充气模拟气藏压力,开展过平衡、近平衡和欠平衡条件下的进液实验以及返排实验模拟不同作业形式下的水相圈闭损害过程,以渗透率损害率、返排率和进液量为水相圈闭损害评价指标。参与了致密砂岩气藏水相圈闭损害评价仪的研制与调试。该评价仪具有功能齐全、自动化程度高、操作方便等优点,可模拟高温高压过平衡、近平衡和欠平衡条件下的水相圈闭损害过程,并可对关键参数如进液量和气相流量实时监测,进液量的监测精度为0.001mL,气相流量的监测精度为0.001mL/min,为致密砂岩气藏水相圈闭损害评价方法的应用提供了设备基础。以致密砂岩气藏水相圈闭损害评价方法为基础,结合所研制的评价仪,编制了致密砂岩气藏水相圈闭损害评价操作规程。以大牛地气田致密砂岩储层为对象,开展了模拟过平衡、近平衡和欠平衡条件下的水相圈闭损害评价实验19组,验证了所撰写的致密砂岩气藏水相圈闭损害评价操作规程和所研制的致密砂岩气藏水相圈闭损害评价仪可用于评价致密砂岩储层水相圈闭损害,并从微观含水分布的角度分析了作业压差和渗透率对水相圈闭损害的影响机理。该评价操作规程可用于致密储层水相圈闭损害程度的评价、不同作业环节中工作液的优选和水相圈闭损害防治措施的效果评价,为致密砂岩气藏的成功勘探和经济开发提供指导。
[Abstract]:Tight sandstone gas plays an increasingly important role in the increase of natural gas reserves and energy supply, and has become a key area of unconventional natural gas exploration and development. Water trap damage induced by water phase retention is one of the main damage types of tight sandstone gas reservoir. Objective evaluation of water phase trap damage is the basis of effective prevention and treatment of water phase trap damage, but the previous evaluation methods of water phase trap damage in tight sandstone gas reservoir have not strong pertinence in the evaluation of water phase trap damage. Due to the limited application of the research results, it is urgent to study the method for evaluating the water phase trap damage in tight sandstone gas reservoirs. Taking typical tight sandstone in Ordos Basin as an object of study, based on the influencing factors and process mechanism of water trap damage, the controlling factors of water facies trap damage evaluation in tight sandstone gas reservoir are summarized. It includes different operation forms, physical properties and pore structure, initial water saturation, gas slippage effect and reservoir sensitivity. Based on the control factors of water trap damage evaluation, the problems existing in the evaluation of water facies trap damage in tight sandstone gas reservoir are analyzed. Cleaning of soluble salt in dense core, establishment of initial water saturation, weakening of gas slippage effect, simulation of gas reservoir pressure, The simulation of water trap damage process and the determination of damage evaluation index in different working forms affect the objective evaluation of water trap damage. In view of the problems existing in the damage evaluation of the above water traps, a method for evaluating the damage of the tight sandstone gas reservoirs is developed. The repeated pressure saturation method is used to wash the salt in the dense core, the initial water saturation is established by using the capillary self-priming method, the back pressure to the limit pressure at the core outlet is applied to weaken the gas slippage effect, and the pressure of the gas-filled simulated gas reservoir is overbalanced. Under the condition of near-equilibrium and under-equilibrium, the water trap damage process was simulated by the liquid feeding experiment and the reflux experiment. The damage evaluation index of the water phase trap was the permeability damage rate, the return discharge rate and the liquid intake rate. Participated in the development and debugging of the water phase trap damage evaluation instrument for tight sandstone gas reservoir. The instrument has the advantages of complete function, high automation, convenient operation, etc. It can simulate the damage process of water phase trap under the conditions of high temperature and high pressure overbalance, near equilibrium and underbalance. It can be used for real-time monitoring of key parameters such as fluid intake and gas flow rate. The monitoring accuracy of the input volume is 0.001mL and the monitoring precision of gas-phase flow is 0.001mL / min, which provides the equipment basis for the application of the method to evaluate the damage of water-phase trap in tight sandstone gas reservoir. Based on the damage evaluation method of water facies trap in tight sandstone gas reservoir and the developed evaluation instrument, the operational rules for evaluating the damage of water facies trap in tight sandstone gas reservoir are worked out. Taking dense sandstone reservoir in Daniudi gas field as an example, 19 groups of water trap damage evaluation experiments were carried out under the conditions of simulating overbalance, near equilibrium and underbalance. It is verified that the operational rules of hydrographic trap damage evaluation for tight sandstone gas reservoir and the developed water phase trap damage evaluation instrument for tight sandstone gas reservoir can be used to evaluate the water phase trap damage in tight sandstone reservoir. The influence mechanism of working pressure difference and permeability on the damage of water phase trap is analyzed from the point of view of microscopic distribution of water cut. The evaluation procedure can be used to evaluate the damage degree of tight reservoir water trap, the optimal selection of working fluid in different operation links and the effect evaluation of water trap damage prevention measures. It provides guidance for successful exploration and economic development of tight sandstone gas reservoir.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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