库车坳陷大北—克拉苏构造带储层敏感性评价及保护措施研究

发布时间：2018-01-16 00:13

本文关键词：库车坳陷大北—克拉苏构造带储层敏感性评价及保护措施研究　出处：《长江大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着我国石油资源开发的进行,低渗透油气田的勘探开发越来越受到人们的重视。库车坳陷大北—克拉苏构造带储层属于低孔、低渗储层,该地区储层具有孔喉半径小、非均质性强、粘土矿物含量丰富和微裂缝发育等特点,这使得该地区储层在生产开发的一系列过程中比较容易受到敏感性损害。本文作者以库车坳陷大北—克拉苏构造带储层为研究对象,通过扫描电镜、X衍射等技术,对该储层的地质特征进行了了解,进行室内敏感性评价实验,在此基础上,对研究区域内致密砂岩储层人工造缝后储层内敏感性损害程度开展了实验研究,并提出敏感性保护及增产措施。主要的研究内容及成果如下:库车坳陷大北—克拉苏构造带储层主要岩石类型为岩屑砂岩,个别为长石岩屑砂岩。岩石整体颗粒较粗,以砾岩、含砾粗砂岩、不等粒砂岩为主。岩石结构成熟度中等,颗粒间以线、凹凸—线接触为主,胶结类型为接触—孔隙和压嵌—-孔隙式。喉道类型整体上处于细喉甚至微喉等级,研究层段内常见的喉道主要为:缩颈状喉道和片状喉道、裂隙性喉道。储层中所发育的粘土矿物大致可分为两种粘土矿物组合:伊利石+绿泥石、伊利石+绿泥石+伊/蒙混层。本文以该储层内4大井区为例,经过室内敏感性评价实验后发现,库车坳陷大北—克拉苏构造带储层整体上表现出强的应力敏及贾敏损害;中等偏强的速敏、水盐敏、碱敏损害;中弱至中强的酸敏损害;较弱水锁损害。通过对比对照分析实验认识到,该区域内致密砂岩储层的主要致敏因素为储层连通性差、孔喉结构复杂、极易堵塞,这与常规储层由于各种粘土矿物含量导致的敏感性损害机理不同。研究层段内发育定量杂基微孔隙及微裂缝,在外部静压力条件下极易被挤压造成渗透性能降低,从而在研究储层内造成强应力敏。针对人工造缝岩心速敏评价,进行了模拟连贯地层速敏损害实验。同时,针对致密储层,本文利用人工造缝研究后期开发增产过程中储层敏感性的损害程度,并与常温常压储层敏感性进行了差异性对比研究,为储层后续开发增产提供依据。考虑到在油田生产开发的过程中,由于储层敏感性损害引起的产量下降现象普遍存在,且其导致的损害往往具有不可逆的特性,针对研究区域存在的各种敏感性损害,进行了相应的保护措施研究。例如,对较强的速、水盐敏损害在入井液中添加颗粒稳定剂和粘土稳定剂来减轻伤害;针对于酸敏损害,为酸液筛选了较为有效的添加剂。
[Abstract]:With the development of petroleum resources in China, more and more attention has been paid to the exploration and development of low permeability oil and gas fields. The reservoir of Dabei-Klassou structural belt in Kuqa depression belongs to low porosity and low permeability reservoir. The reservoir in this area is characterized by small pore throat radius, strong heterogeneity, rich clay mineral content and microfracture development. This makes the reservoir in this area more vulnerable to sensitivity damage in a series of production and development process. This paper takes the reservoir of Dabei-Klassou structural belt in Kuqa depression as the research object through scanning electron microscope. The geological characteristics of the reservoir are understood by X-ray diffraction techniques, and the laboratory sensitivity evaluation experiments are carried out on this basis. The sensitivity damage degree of tight sandstone reservoir in the study area after artificial fracturing is studied experimentally. The main research contents and results are as follows: the main rock types of the reservoir in the Dabei-Klassou structural belt of Kuqa depression are lithic sandstone. Some of them are feldspar lithic sandstone. The whole rock grain is coarse, mainly conglomerate, gravel-bearing coarse sandstone, unequal grain sandstone. The structure maturity of rock is medium, the grain is line, concavity and line contact. The types of cementation are contact-pore and pressure-pore. The larynx type is in the level of fine throat or even microlarynx as a whole. The common throat in the study layer is: neck-necked throat and flaky throat. The clay minerals developed in the reservoir can be divided into two types of clay mineral assemblage: Illite chlorite, Illite chlorite / mixed layer. Through the laboratory sensitivity evaluation experiments, it is found that the reservoir of the Dabei-Klassou structural belt in Kuqa depression shows strong stress sensitivity and damage by Jia Min as a whole. Medium strong speed sensitive, water salt sensitive, alkali sensitive damage; Acid sensitivity damage from moderate to strong; The main sensitizing factors of tight sandstone reservoir in this area are poor connectivity, complex pore throat structure and easy plugging. This is different from the mechanism of sensitivity damage caused by various clay mineral contents in conventional reservoirs. Under the condition of external static pressure it is easy to be extruded to reduce permeability thus causing strong stress sensitivity in the study reservoir. Aiming at the evaluation of velocity sensitivity of artificial fracturing cores an experiment of simulating the damage of velocity sensitivity in coherent formation is carried out at the same time. In this paper, the damage degree of reservoir sensitivity in the later development and production increase process is studied by artificial fracturing, and the sensitivity of reservoir is compared with that of normal pressure reservoir at room temperature. In the process of production and development of oil fields, the phenomenon of production decline caused by reservoir sensitivity damage is widespread, and the damage caused by it is often irreversible. In view of the sensitivity damage existing in the study area, the corresponding protection measures are studied. For example, for the strong speed, the water salt sensitive damage is reduced by adding particle stabilizer and clay stabilizer to the well fluid. In view of acid sensitivity damage, more effective additives were screened for acid solution.
【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13;TE258.2

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