【作者】 杨磊；

【导师】 邓礼正； 陆正元；

【作者基本信息】 成都理工大学 ， 油气田开发地质， 2009， 硕士

【摘要】 子洲气田是鄂尔多斯盆地的主力气藏之一,其山2气藏截止2005年底已探明天然气储量922.6×108m3,随着勘探开发的深入,在大面积开发天然气的同时,也在该区出现了大量的产水井,子洲地区共出产水井31口,这些井产水量差别悬殊,最小产水井产水0.3m3/d,最大产水井产水46.6m3/d。这些产水井严重地影响了该地区的开发进程和开发效果。特别是对开发井的部署带来极大的风险,这就要求找出研究区的气水分布规律,预测研究区的气水相对分布区,为提高布井成功率、高效建产提供必要的前提条件。因此,及时开展该地区储层特征及气水分布规律的研究就显得尤为重要。本文从山23段砂体分布和储层特征入手;以高分辨率层序地层分析为手段研究山23段小层对比及连通情况;在应用测井数据交汇图法和正态分布法对单井储层流体识别的基础上;对气水分布剖面进行研究;并结合地层水的水化学资料;分析得出了工区的气水分布规律和控制因素,指出了有利勘探区块。主要取得了以下认识和成果:1.山23段底部有稳定的砂体发育,欠发育中上部砂体,在平行河道走向上砂体连通性较好。山23段储层孔隙度和渗透率低,属低孔低渗的致密砂岩储层,孔隙类型以粒间孔、粒间溶孔为主,孔隙结构较好。以Ⅱ类和Ⅲ类储层为主,在层间、层内和平面上表现出强烈的储层非均质性。2.山23段划分为一个中期基准面旋回层序,包含了3个短期旋回层序。其中SSC2和SSC3在研究区内普遍发育,个别井缺失SSC1短期旋回层序,SSC1短期旋回层序的地层岩性主要以太原组顶部的黑色海相泥岩或灰岩为主,主要起到海陆相过渡时期的填平补齐作用。山23段共包括两种层序结构类型,分别是向上“变深”非对称型旋回层序(A型)和对称型旋回层序(C型),并细分为4种亚类型。从层序地层格架中发现山23段存在两套砂体,分别发育在SSC2和SSC3短期旋回中,研究区北部SSC3短期旋回欠发育,两套砂体在中部洲35-28井-榆64井区叠置在一起。3.山23段地层水为CaCl2型,属于地层古残留水,并识别出了两类地层水:边(底)水(矿化度>100g/L)、透镜体水(矿化度<80g/L)。产边(底)水的井主要位于构造低部位,产水量大,产微气;产透镜体水的井主要位于含气区内部及构造相对高部位或主砂体带的边部,产水量小,并伴随气产出。4.受构造特征和沉积相带展布的影响,研究区山23段砂体呈南北向的条带状分布,北部砂体较厚,南部相对较薄;主砂体带内存在南北两个较大的天然气富集区;每个天然气富集区的南部、西南部构造低部位均存在边水区,导致研究区内存在两个气水界面;主砂体东侧受储层物性影响,为高含水的致密砂层,测试一般不产流体或产流体极少,主要为干层。5.经研究确定榆48井区附近砂体较厚、有较好的储层物性,远离气水界面,是有利的勘探区域。更多还原

【Abstract】 Zi-Zhou gas field is a main gas-production zone in the Ordos Basin and the S2 gas field has a proven gas reserve of 922.6×108m3 by 2005. With the exploratory development, as the gas production developed in large area, a great many water production wells appeared in this field. There were totally 31 water production wells and their production varied from 0.3m3/d to 46.6m3/d. These wells had badly influenced the development effects and development process of this area, especially increased the risk of the disposition of exploitation wells. So we should find the gas-water distribution pattern and forecast the gas-water distribution in the researching area as to enhance the deployment success ratio and to build up higher deliverability. So it is very important to study the reservoir characteristics and gas-water distribution pattern of this area immediately.The paper researches the distribution of the sand-body and the characteristics of reservoir in Shan-2 member. Member comparisons and connectivity is studied based on the high resolution sequence stratigraphy methods; the fluid recognition in single well is studied by the methods of cross plot and normal distribution using well log data; we have also studied the gas-water distribution in profile; with data of hydrochemical water information, we have acknowledged the pattern and controlling factors of gas-water distribution and we have pointed out the favorable exploration targets. The results are:1. The basal sand body of S23 is steady, middle–head of the sand body is understable and the sand body along the river channel is well connected. The S23 reservoir belongs to low porosity and permeability reservoir; its pore types are mainly intergranular pore and intergranular dissolved pores and the pore structure is good. The reservoir are mainly composed of typeⅡ,typeⅢ. The reservoir conduct intensely leterogeneity in plane and internal. 2. The S23 is divided into a middle base-level cycle which contains three short-term base-level cycles. All of the short-term base-level cycles, the SSC2 and SSC3 cycles are widespread in the area and the SSC1 cycle is lost in several wells. The lithology of the SSC1 cycle is mainly black marine mudstone or marine limestone of the top of Taiyuan formation, these stones were used to fill and level up during the period of continental oceanic facies varied. The 3rd member of Shan-2 formation contained two types of sequence structures which are asymmetrical cycle sequences (Type A) and symmetrical cycles sequences (Type C). The sequence structures are divided into 4 sub-types. From the study of the high resolution stratigraphy frameworks we know that there are two sand bodies in the S23. The sand bodies grow in the SSC2 and SSC3 short-term cycles separately. The SSC3 short-term cycle is under-developed in the north of the research area. The sand bodies superposes from Zhou 35-28 to Yu64 well fields in the middle of the research area.3. S23 water is CaCl2 and belongs to residual water in the formation. We have identified two types of formation water: edge and bottom water (salinity>100g/L) and lenticular water (salinity<80g/L). The wells that produce edge and bottom water are mainly in the downstructure location and yield much water and little gas; the wells that produce lenticular water are in the relatively higher location or at the edge of the main sand-body and they yield a little water with some incidental gas.4. Affected by the structural feature and the distribution of sedimentary facies, the sand body of S23 in the research area ranges from north to south in a banded shape, the northern part of the sand body is thicker while the southern part is thinner; two gas-rich zones are located in the southern and northern part of the main sand body; in each of the gas-rich zones, edge water zones exist in the south and southwest downstructure location, which forms two gas-water interfaces in the research area; the east part of the main sand body is affected by the reservoir characteristics, it is tight sand with high water-cut and usually produces little or no fluid when testing, it is mainly dry bed.5. Research results demonstrate that the sand body near Y48 is thicker、with good reservoir properties and far away gas-water surface , and it is the advantageous exploration area.更多还原