大港油田调整井地层孔隙压力预测研究

发布时间：2018-03-26 09:00

本文选题：地层孔隙压力　切入点：地质建模　出处：《长江大学》2015年硕士论文

【摘要】：陆地油田经历依靠天然能量开采、注水开采等阶段后进入油田开发中后期,为了稳定油气产量和提高原油采收率必须通过钻调整井不断完善开发井网。已开发油气田经过若干年的注采势必造成储层压力衰竭,打破原始压力平衡体系,导致调整井钻进过程遇到压力亏空区和憋压区,易发生漏、阻、卡、塌、喷等复杂事故,严重时甚至导致井眼报废。因此,准确预测调整井地层孔隙压力横纵向压力分布是安全优快钻井的基本保障。本论文以大港沈家铺油田G128断块为研究对象,以经过15年的注水开采后油水井套损严重致使井网瘫痪,开发矛盾突出,断块稳产难度大；为了提高断块的开发水平,通过钻调整井完善开发井网为研究背景。综合多学科深入开展已开发油气田异常地层压力预测研究,从钻井、地质建模、油藏数值模拟三方面计算、分析、模拟出原始地层压力和衰竭后现今地层压力,总结出G128断块地层压力横纵向分布规律。其主要研究成果如下：(1)结合G128断块地层岩性特征及初期钻井资料优选出声波时差法计算模型。通过原始探井地层压力实测值反算出区块的伊顿指数,再计算出区块有代表性的9口井的原始地层孔隙压力,并以此绘制了原始地层孔隙压力横纵向分布图；在不考虑压力传递对盖层强度参数影响的情况下,采用Morita的理论计算衰减后盖层压力,同时绘制现今地层孔隙压力横纵向分布图。经分析G128断层原始地层孔隙压力在主力开发层系孔一段枣V以上基本属于正常压力体系,当量密度在0.95-1.15g/cm3之间；在主要储层孔一段枣V出现局部异常压力地层,当量密度在1.05-1.25g/cm3之间。经过15年的注水开采后,现今储层地层压力当量密度衰竭至0.96左右；根据Morita理论计算盖层地层孔隙压力衰减,可得储层压力衰减对垂直距离30m内盖层孔隙压力衰减影响较为明显,对超过垂直距离30m的盖层由于受到地层岩性、孔隙度、渗透率等因素影响,地层压力衰减并不明显。(2)收集整理G128断块地质构造图件、断层数据、分层数据及井位数据等建立三维地质模型。在油藏孔隙度、渗透率、含油饱和度基本三维属性模型的基础上,首次添加原始上覆岩层压力、原始地层孔隙压力及衰竭后现今地层孔隙压力三维属性模型；通过地质模型的剖面分析,G128模型孔隙度和渗透率呈现很好的对应性；受沉积环境及储层非均质影响,孔一段枣V油组上下两套油层之间、同一套油层内部层间地层孔隙压力差异大。同时油层主要分布在储层的中上部的高孔、高渗小层中。(3)导入G128断块J39-49井区确定性粗模型,结合生产动态数据模拟孔一段枣V储层压力衰竭。本次数值模拟中历史拟合的方法是采用定液量拟合累积产油量的办法,对模型加以修整,使之产生的动态与实际动态基本一致,最终模拟出孔一段枣V地层压力衰竭曲线图及立体图。通过储层压力衰竭曲线图分析可知G128断块储层压力衰竭1MPa左右,压力保持情况较好；对单井立体剖面图分析可知越靠近油井,储层压力衰竭越大。
[Abstract]:Land oil by natural energy exploitation, water flooding stage in the late stage of oilfield development, in order to stabilize oil production and enhance oil recovery by drilling must constantly improve the wells. After several years has been the development of oil and gas injection reservoir pressure will cause failure, break the original pressure balance system, cause the adjustment well drilling process encountered pressure deficit area and pressure, prone to leakage, resistance, card, collapse, spray and other complex accidents, even when serious damage of the well. Therefore, the accurate prediction of formation pore pressure of adjust well the longitudinal pressure distribution is the basic guarantee of safety and fast drilling. In this thesis, Dagang Shen Pu oilfield G128 fault block as the research object, through the water flooding after 15 years of casing failure wells resulting in paralysis, development contradiction, block production; in order to improve the development level of fault block, Through drilling improve wells as the research background. The comprehensive multidisciplinary development has been the development of abnormal formation pressure of oil and gas prediction research, from drilling, geological modeling, simulation, analysis of three aspects of reservoir numerical simulation, the original formation pressure and failure after the present formation pressure, summed up the G128 fault block formation pressure of horizontal and vertical distribution law. The main results are as follows: (1) combined with the G128 fault block lithology and initial drilling data optimized sonic model. Through the original formation pressure wells measured values calculated block Eaton index, and then calculate the original block of 9 representative wells formation pore pressure, and draw the original pore pressure distribution in horizontal and vertical; without considering the pressure transfer to cover strength parameters under the condition of pressure calculation using Morita cover attenuation theory, at the same time Now draw the pore pressure of horizontal and vertical distribution map. By analysis of G128 fault original pore pressure in the main layer series of development in Kongdian Zao V above belong to the normal pressure system, the equivalent density between 0.95-1.15g/cm3; local abnormal formation pressure in the main reservoir of Kongdian Zao V, the equivalent density between 1.05-1.25g/cm3 after injection. After 15 years of mining, the present reservoir formation pressure equivalent density failure to around 0.96; according to the Morita formula cover pore pressure attenuation, reservoir pressure attenuation can be more obvious to the vertical distance from the 30m inner layer pore pressure attenuation effect, to cover more than a vertical distance of 30m due to lithology, porosity, influence the permeability and other factors, the formation pressure attenuation is not obvious. (2) collected G128 fault block geological maps, fault data, hierarchical data and location data to build three Dimensional geological model. The permeability in the reservoir porosity, oil saturation, based on basic 3D attribute model, first add the original overburden pressure, pore pressure and failure after the original current pore pressure three-dimensional property model; through the section of geological model analysis, porosity and permeability of the G128 model showed a good correspondence by; sedimentary environment and reservoir heterogeneity influence between Kongdian Zao V oil group on two sets of oil, the difference of pore pressure with a reservoir internal layer. At the same time high porosity reservoir is mainly distributed in the reservoir in the upper part of the small, hypertonic layer. (3) into the G128 block of deterministic J39-49 wells coarse model, combined with dynamic production data simulation of reservoir pore pressure failure V jujube section. In the historical simulation method fitting numerical adopt fixed cumulative oil production fluid volume fitting method, the model to make the overhaul. Dynamic and actual dynamic generated are basically the same, the final simulation of Kongdian Zao V formation pressure failure curve and three-dimensional map. The reservoir pressure depletion curve analysis of G128 fault block reservoir pressure failure 1MPa, pressure keeping in good condition; the single well cross section analysis that is close to the oil reservoir the greater the pressure depletion layer.

【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE331

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