海上N气田低孔渗气藏探井测试解堵增产技术研究

发布时间：2018-08-17 14:49

【摘要】：N气田为我国近海某凹陷具有代表性的低孔渗气田,此类气田探井测试过程中采用钻杆进行测试。但由于N气田主力储层本身物性差、压力系数不高,加之钻完井过程中对储层造成的伤害,常出现测录井显示好的层位测试效果差甚至测试无产出的情况,使得高成本的海上测试成功率低,导致有可能错过新气藏的发现。本文以文献调研、机理分析、室内实验、软件模拟为主要研究手段,系统研究了N气田探井测试效果差的原因及相应的增产测试工艺,主要完成内容及取得的成果和认识如下： (1)通过调研现场资料及对取心井岩芯进行岩性、物性分析,明确了其主力储层G组储层存在孔渗低,压力系数不高、岩石胶结致密等特性,总体来讲储层物性偏差。 (2)通过室内敏感性评价实验,明确了G组储层的敏感性特征,即弱速敏、中等偏弱水敏、弱盐敏、弱碱敏、中等偏强酸敏。通过入井工作液对储层伤害的实验和机理研究,明确了水锁伤害是造成储层伤害及测试效果不佳的主因。 (3)基于N气田主力储层G组测试低产原因诊断结果,充分考虑储层高温、管柱条件及海上作业环境等条件限制,对工艺措施进行适应性分析后,设计出了一整套解堵增产测试工艺,其技术核心为地下自生酸酸化解堵技术,主要研究成果包括优选评价出了自生酸解堵液体系,利用软件模拟了自生酸段塞在井筒内混合情况,设计出了多级交替段塞注入的自生酸酸化解堵增产测试工艺。对该工艺在现场进行了两井层的应用,增产效果显著。本论文的研究内容及成果为海上低孔渗N气田探井增产测试及低孔渗气藏的有效发现提供了强有力的理论支撑和技术保障,而且为类似海上低孔渗气田增产测试提供了可借鉴的研究方法和技术思路,具有一定的推广价值。
[Abstract]:N gas field is a representative low porosity and permeability gas field in an offshore sag of China. Drilling pipe is used in the testing process of the exploration well in this kind of gas field. However, due to the poor physical property of the main reservoir in N gas field, the low pressure coefficient and the damage caused to the reservoir during drilling and completion, it is often found that the logging shows a good interval test effect and even the test is not productive. The low success rate of high-cost offshore tests makes it possible to miss the discovery of new gas reservoirs. Based on literature investigation, mechanism analysis, laboratory experiments and software simulation, this paper systematically studies the causes of poor testing effect of exploration wells in N gas field and the corresponding test techniques for increasing production. The main contents, achievements and understandings are as follows: (1) through investigation and investigation of field data and analysis of lithology and physical properties of core wells, it is clear that the main reservoir G reservoir has low porosity and permeability and low pressure coefficient. In general, the reservoir physical property deviates from the characteristics of rock cementation and compactness. (2) through the laboratory sensitivity evaluation experiments, the sensitivity characteristics of G group reservoirs are defined, namely, weak velocity sensitivity, moderate weak water sensitivity, weak salt sensitivity, weak alkali sensitivity, and so on. Moderate strong acid sensitivity. Through the experiment and mechanism study on reservoir damage caused by working fluid into well, it is clear that water lock damage is the main cause of reservoir damage and poor test effect. (3) based on the diagnosis result of low production cause of G group test of main reservoir in N gas field, Considering the limitation of reservoir high temperature, pipe string condition and offshore working environment and so on, after analyzing the adaptability of technological measures, a whole set of plugging and increasing production test technology has been designed, the core of which is the underground acid-acid plugging technology. The main research results include the optimal selection and evaluation of the autogenous acid plugging solution system, the simulation of the mixing of the autogenous acid slug in the wellbore by software, and the design of the test process for increasing the production of the plugging by injecting the autogenous acid into the multi-stage alternating slug. The process has been applied to two well layers in the field, and the effect of increasing production is remarkable. The research contents and results of this paper provide strong theoretical support and technical support for the exploration well production test and the effective discovery of low porosity and permeability gas reservoir in the offshore low porosity and permeability N gas field. It also provides the research method and technical train of thought for the stimulation test of similar offshore low porosity and permeability gas field, and it has certain popularization value.
【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】：TE53

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