【作者】 刘伟；

【导师】 王洪辉；

【作者基本信息】 成都理工大学 ， 油气田开发工程， 2008， 博士

【摘要】 目前,我国在探明未动用的地质储量中大部分为低渗透油田储量,所占比例高达72.8%。由于低渗透油田开发效果和经济效益较差,油层伤害较重,使低渗透油田开发非常困难。因此如何减少油层损害,并对油层进行有效改造,进而提高低渗透油田开发效益,对我国石油工业持续稳定发展有至关重要的作用。本论文以基山低渗透砂岩体为例,对低渗透油藏的成因及主控因素、低渗透油藏储层伤害机理、低渗透油藏储层保护技术进行了详细的探讨,提出了相应的储层改造措施。通过研究,认识到导致低渗透油藏储层渗透率低,常规试油产量偏低、稳产期较短且无法投入有效开发的主要原因除了与深层油藏的物性差和天然能量不足有关外,还与低渗透油藏的油层伤害特性有关,也与储层改造工艺技术的不适应有关。通过研究,主要取得了以下成果和认识:1.基山低渗透砂岩油藏主力储层岩石结构致密,骨架颗粒轮廓不清晰,粒间孔隙分布不均,存在大孔隙和微孔隙。储层孔隙度为中到低孔、渗透率为低渗到特低渗,造成储层渗透率低的主要成岩作用是压实作用和胶结作用。2.低渗透油藏伤害机理与其它孔隙性油藏伤害机理并无本质上的不同,主要存在固相堵塞、化学敏感、水锁、结垢等方面的损害,但由于低渗透储层地质和渗流特征的特殊性,致使不同损害的伤害程度有所不同。研究表明,基山砂岩体低渗透储层基本伤害形式包括敏感性伤害、固相堵塞、水锁和化学结垢等四类;3.针对钻井、完井过程中普遍存在的储层固相与液相伤害,在实验研究的基础上,完善了潜在酸、聚合物和水伤害解除剂配方,优化了复合解堵体系。取得了较为理想的效果。4.针对早期VES压裂液存在伤害储层有效渗透性和抗高温能力差的弱点,加强了相应的研究,研制出新型水基压裂液体系。该体系不含高分子聚合物,可完全破胶化水,对裂缝导流能力基本不具有负面影响。5.形成了一套低渗透储层压裂改造与评价技术,并在基山低渗透砂岩油藏进行现场试验,取得了较好的效果。更多还原

【Abstract】 Now, reserves of low permeability reservoirs take the most part of unused reserves in our country, which take the proportion of 72.8 percent. It is difficult to develop the low permeability reservoirs because of the reasons such as the developing effect and economic benefit is low, reservoir damages is heavy, etc. therefore enhancing the developing effect of low permeability reservoirs will take key affect for sustainable and steady development of our country’s petroleum industry through the method of decreaseing reservoir damages and taking effective reservoir stimulation.In this article, the author take Jishan low permeability reservoir as example to discuss the questions below: the origin and the master control factors of low permeability reservoirs, the mechanism of reservoir damages of low permeability reservoirs, the techniques of reservoir protection of low permeability reservoirs and how to stimulate the reservoirs. Through the research , the author recognize the main reasons including low physical property and low natural depletion oil recovery, character of formation damages of low permeability reservoirs, the disconformity of reservoir stimulation techniques which lead to low permeability of reservoirs, the low production of formal well testing and the shortness of production plateau. The main results as follow:1. Rock texture of the principal producing formation of Jishan low permeability reservoir is density, the framework grain outline is not clear, the distribution of intergranular pore is unequal which include macropore and micropore. The porosity of the reservoir alter form middle porosity to low porosity, the permeability alter from low to particular low. The diagenesis which cause the low permeability of reservoir are compaction and cementation.2. mechanism of formation damages of low permeability are not different in essence with which of other porous reservoirs, the damages generally are sold plugging, chemical sensibility, water blocking, scale formation, etc. but the degree of damages of different formation damage are differ because of particularity of reservoir geology and seeping character of the low permeability reservoirs. The research indicate that the reservoir damages of Jishan low permeability reservoir are sold plugging, chemical sensibility, water blocking and scale formation.3. Aim at the solid and liquid damages of reservoir which usually exist during the course of drilling well and completion, the author perfect the receipt of dissolve agent of latent acid, polymer and water, optimize multiple broken down system, on the basis of experiment research. All of which above obtain good effect.4. because the early VES fracturing fluid is of two severeness weakness which is that damages the effective permeability of reservoir and low capability of repeling high temperature, we develop new type water base fracturing fluid system after the effort of working person. Which are free of macromolecule polymer, can gelout completely, do not have negative influence to the diversion capability of fracture.5.After the research, the author has been formed a set of technique of reservoir stimulate and evaluation of low permeability. This set of technique has been used in Jishan low permeability reservoir, which obtain good effect.更多还原