川西GMZ构造沙溪庙组储层改造工艺技术研究

发布时间：2018-02-24 20:40

本文关键词： 川西凝析气藏防乳化压裂液脉冲式柱塞加砂控压返排　出处：《西南石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：GMZ构造位于川西坳陷中段,预测储量为1007.77×108m3,是川西地区重要的建产区块。截止2013年12月,GMZ主体区块下沙溪庙组共投产9口气井,已压裂投产的井中出现了压后排液过程中产凝析油、自然返排率较低且伴有出砂等现象,导致压裂效果不理想。针对前期压裂中存在的问题,本论文在前人研究基础上,综合运用石油与天然气地质、储层保护等学科的知识和方法,对GMZ构造沙溪庙组前期压裂中存在的问题进行了大量的深入研究,取得了如下成果： ①在对GMZ构造沙溪庙组储层地质特征认识的基础上进行了大量的室内实验评价,包括流体物性实验、敏感性实验、岩石力学及地应力实验、岩芯伤害实验等,研究认为GMZ构造沙溪庙组气藏为微含凝析油的低渗致密凝析气藏,压裂过程中的反凝析现象对储层伤害率超过80%,且储层岩石在酸泡后易出砂； ②针对GMZ构造沙溪庙组储层压裂后返排液中出现凝析油、返排率低且伴有地层出砂的现象,对GMZ沙溪庙气藏压裂液各添加剂进行优选和加量优化后形成GMZ构造沙溪庙组气藏防乳化压裂液配方；此外,为减少地层出砂,通过支撑剂嵌入与运移实验,确定最佳支撑剂粒径组合为80%的30/50目+20%的40/70目陶粒； ③通过室内物模实验和数模实验,验证了脉冲式柱塞加砂技术减少入地液量的可行性,并对工艺参数进行优化,形成了GMZ构造沙溪庙组储层脉冲式柱塞加砂工艺技术；通过现场试验证明该技术不仅可有效减少入地液量,还可在一定程度上提高裂缝导流能力； ④对液氮降低液柱压力和储层增能效果进行计算,证实液氮助排提高压裂液返排率的可能性,并建议水平井在后四段进行液氮伴注；针对GMZ构造沙溪庙组主要三条分流河道沉积相砂体的流体实验研究结果具有不同的露点压力,分别形成三条河道控压返排工艺措施。液氮助排和控压返排技术在现场均取得较好效果。从现场实验效果上来看,各项工艺技术在现场使用情况良好。2014年压裂14口井平均返排率为60.2%,较2013年(50.2%)提高10.0%,且返排过程中未发现凝析油与地层砂的产出；压后在平均油压13.5MPa,套压12.4MPa下测试产量为4.1537×104m3/d。研究形成的GMZ构造沙溪庙组储层改造工艺技术效果良好,建议在该区广泛应用。
[Abstract]:The GMZ structure is located in the middle section of the western Sichuan depression, and its predicted reserves are 1007.77 脳 108m3.It is an important building and producing area block in the western Sichuan area. As of December 2013, nine gas wells were put into operation in the Xiashaximiao formation, the main block of GMZ. Condensate is produced in the process of fracturing and putting into production, and the natural rate of backflow is low and sand production is accompanied, which leads to the unsatisfactory effect of fracturing. In view of the problems existing in the early fracturing, this paper, on the basis of previous studies, synthesizes the knowledge and methods of petroleum and natural gas geology, reservoir protection, etc. The problems existing in the early fracturing of Shaximiao formation in GMZ structure are studied deeply, and the following results are obtained:. 1 based on the understanding of the geological characteristics of the Shaximiao formation reservoir in the GMZ structure, a large number of laboratory experiments have been carried out, including fluid physical property experiment, sensitivity experiment, rock mechanics and in-situ stress experiment, core damage test, etc. It is considered that the Shaximiao formation gas reservoir in GMZ structure is a low permeability condensate gas reservoir with micro condensate oil. The damage rate of the reverse condensate phenomenon to the reservoir is over 80 during fracturing, and the reservoir rock is easy to produce sand after acid bubble. (2) in view of the phenomenon of condensate oil appearing in the back drainage fluid of Shaximiao formation reservoir of GMZ structure after fracturing, the rate of back discharge is low and the sand is produced by formation. The formula of anti-emulsification fracturing fluid of Shaximiao formation gas reservoir with GMZ structure is formed by optimizing the additives of fracturing fluid of Shaximiao gas reservoir in GMZ Shaximiao gas reservoir, in addition, in order to reduce formation sand production, the experiments of embedding and migration of proppant are carried out. The optimum particle size combination of proppant is 30/50 mesh 20% 40/70 mesh of 80%; (3) the feasibility of using pulse plunger to add sand to reduce the amount of liquid into the ground is verified by indoor physical model experiment and digital model experiment, and the technological parameters are optimized to form the technology of pulse plunger sand addition in Shaximiao formation reservoir of GMZ structure; It is proved by field test that the technology can not only effectively reduce the amount of liquid entering the ground, but also improve the fracture conductivity to a certain extent. (4) calculating the effect of liquid nitrogen reducing liquid column pressure and increasing reservoir energy, confirming the possibility of liquid nitrogen assisted drainage to increase the rate of back discharge of fracturing fluid, and suggesting that the horizontal well should carry out liquid nitrogen injection in the latter four stages; According to the fluid experimental results of three distributary channel sedimentary facies sand bodies in Shaximiao formation of GMZ structure, there are different dew point pressures. The process measures of controlled pressure back drainage were formed in three river channels respectively. Both liquid nitrogen assisted drainage and controlled pressure back drainage technology achieved good results in the field. From the point of view of field test results, the application of each technology in the field is good. In 2014, the average recovery rate of 14 wells fracturing is 60.2, which is 10.0 higher than that of 2013 (50.2), and no condensate oil and formation sand are found in the process of backflow. The average oil pressure is 13.5 MPA and the test output is 4.1537 脳 10 ~ 4 m ~ (3 / d) d at the average oil pressure of 12.5 MPA. The GMZ structure Shaximiao formation reservoir reconstruction technology has good effect and is suggested to be widely used in this area.
【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】：TE357

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