虎狼峁精细分层注水油藏研究

发布时间：2018-06-14 17:47

本文选题：低渗透 + 分层注水　；参考：《长江大学》2015年硕士论文

【摘要】：国内外低渗透油田的开发已有近百年的历史,其中美国早在1871年发现并开发了世界著名的勃莱德福低渗透砂岩大油田(平均渗透率7.510×10-3μm2、平均孔隙度15%)。在我国低渗透油田开发也有着悠久的历史,1907年9月10日,我国陆上钻成第一口油井—延长油田1号井,其产层就是举世闻名的特低渗透层—三叠系延长统油层。从国内外有关报道情况来看,对低渗透油田基本的地质特征和开发特征有如下认识：(1)储层物性差,渗透率低。由于颗粒细,分选差,胶结物含量高,经压实和后生成岩作用使储层变得十分致密,渗透率一般小于100×10-31.μm2,少数低于1.0×10-3μm2：(2)储层孔隙度一般偏低,变化幅度大。大部分在7%～20%分布,个别高达25%(美国巴罗岛油田),多数低渗透油田的有效厚度有限,所以储量丰度普遍偏低；(3)原始含水饱和度较高,原油物性较好。一般含水饱和度在30%—40%,个别高达60%(美国的东堪顿油田),原油密度多数小于0.85,地层原油粘度多数小于3 mPa.S。这就决定了低渗透油田虽能注水,但水淹速度偏快；特低渗透油藏的显著特征是储层渗透率远低于中高渗透油藏、渗流存在启动压力梯度、部分微裂缝发育,因此,特低渗透油藏分层注水标准有其特殊性：(1)特低渗透油藏如长庆虎狼卯长6油藏裂缝较发育,对注水开发效果影响较大,因此对隔层厚度及稳定性要求更高；(2)层段内小层数根据层段内渗透率变异系数、突进系数进行控制,均质性越差,小层数越少；(3)特低渗透油藏渗透率特低、存在启动压力梯度,水井一般需要压裂投注,需要更高的注水压力才可正常注水；历年测试吸水强的层尽量单卡单注;(4)低渗透油藏注水形成优势通道后,目前无有效调剖堵水技术,因此应对注水量进行控制,防止油藏在低采出程度期油井大面积水淹；长庆超低渗透油藏自规模开发以来,受储层吸水差异影响,逐步表现出水驱动用程度低、地层压力保持水平低及递减大等问题。近年来,为改善吸水状况,提高水驱动用程度,使纵向分层注水分布均匀,进行分层注水。目前超低渗油藏主要采用两层分注,为满足精细注水要求,还需开展多层分注。本文在把握油水流动特征的基础上,对油藏注采系统进行了等效表征,建立了能够综合考虑压缩性和关停井情况的井间动态连通性模型。在此之上基于贝叶斯理论和投影梯度法,建立了连通性模型整体约束优化方法,为动态分析、裂缝建模提供了新的方法和数据。创新建立了分层注水标准。在非均质性影响水驱效率分析基础上,确定分层注水后,综合运用开发动态、动态监测及数值模拟研究方法,建立油藏精细分层注水技术标准,即层间渗透率级差小于3；隔层厚度≥1m,为精细分层注水方案的制定提供依据。运用油藏工程、开发动态数理统计、经验法及数值模拟方法相结合,制定出地层压力、井底流压及注水强度等精细注水政策。油藏合理地层压力12.1MPa;合理井底流压6.0—7.5MPa模拟区合理注采比为1.1,合理采液速度1.7%,预测方案采出程度12.81%(模拟十年),累产油26.65万方。
[Abstract]:The development of low permeability oil fields at home and abroad has a history of nearly one hundred years. In 1871, the United States discovered and developed the world famous Bradford low permeability sandstone oil field (the average permeability is 7.510 * 10-3 Mu m2, the average porosity is 15%). In China, the development of low permeability Oilfield has a long history. In September 10, 1907, China was drilled on the land. An oil well - Yanchang oilfield No. 1 is well known as the ultra low permeable layer of the Triassic Yanchang formation. From the relevant reports at home and abroad, the basic geological characteristics and development characteristics of low permeability oilfields are as follows: (1) poor physical property and low permeability. The compaction and metabenetic diagenesis make the reservoir very dense, and the permeability is generally less than 100 x 10-31. Mu m2, and the porosity of a few below 1 x 10-3 mu m2: (2) is generally low and large. Most of them are distributed in 7% to 20%, up to 25% (American barrow island oil field), and the effective thickness of most low permeability oil fields is limited, so the reserves abundance is common. All times are low; (3) the original water saturation is high and the crude oil property is better. The general water saturation is 30% to 40%, the individual is up to 60% (East Kanton oil field in the United States), the density of crude oil is less than 0.85, and the viscosity of the crude oil is mostly less than 3 mPa.S., which determines that the low permeability oil field can be injected with water, but the water flooding speed is fast; the remarkable low permeability reservoir is significant. The characteristic is that the reservoir permeability is far lower than the medium high permeability reservoir, the seepage flow has the starting pressure gradient and the partial micro crack development. Therefore, the stratified water injection standard of the ultra-low permeability reservoir has its particularity: (1) the fracture of the reservoir of the ultra low permeability reservoir, such as the Changqing tiger Mao Chang 6 reservoir is more developed, and has a great influence on the water injection development effect. Therefore, the thickness and stability of the partition are made. Higher requirements are required; (2) the small layers within the layer are controlled according to the permeability variation coefficient and the penetration coefficient in the layer, the worse the uniformity is, the less the number of small layers; (3) the permeability of the ultra-low permeability reservoir is very low, the starting pressure gradient exists, the well usually needs fracturing injection, and the higher water injection pressure is needed to the normal water injection; the water absorption strength is tested over the years. 4. (4) there is no effective profile control and water plugging technology at present after water flooding in low permeability reservoir, so water injection should be controlled to prevent oil reservoir from flooding in large area of oil wells at low production level. Since the low permeability reservoir of Chang Qingchao has been developed from scale, it is affected by the difference of reservoir water absorption and gradually shows the driving course of water production. In recent years, in order to improve water absorption, improve water flooding and improve water flooding, the vertical stratified water injection is evenly distributed and stratified water injection is carried out in recent years. At present, two layers of injection are used in ultra-low permeability reservoirs to meet the requirements of fine water injection. On the basis of the equivalent characterization of the reservoir injection and production system, the dynamic connectivity model which can comprehensively consider the compressibility and shutdown conditions is established. Based on the Bayesian theory and the projection gradient method, the integral constraint optimization method for the connectivity model is established, which provides a new method and number for the dynamic analysis and the fracture modeling. On the basis of the analysis of water flooding efficiency analysis on the basis of non homogeneity influence water flooding efficiency, the comprehensive utilization of development dynamic, dynamic monitoring and numerical simulation research methods are used to establish the technical standard of reservoir fine stratified water injection, that is, the interlayer permeability differential is smaller than 3, and the thickness of the partition is more than 1m, which is a fine stratified water injection scheme. The reservoir engineering, the development of dynamic mathematical statistics, the experience method and the numerical simulation method are combined to make the fine injection policy of formation pressure, bottom hole flow pressure and water injection strength. The reasonable formation pressure of the reservoir is 12.1MPa; the reasonable injection production ratio of the reasonable bottom hole flow pressure 6 to 7.5MPa simulation area is 1.1, the reasonable mining speed is 1.7%, the forecast party is expected. The level of the case was 12.81% (simulated for ten years), and the cumulative output of oil was 266 thousand and 500.
【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】：TE357.6

【参考文献】