摘要
针对伊通盆地莫里青油田低孔低渗储层注水开发的需求,开展了储层损害评价和注入水改善措施研究。通过对该油藏储层岩性、物性与黏土矿物特征的分析,揭示了储层存在速敏、碱敏及水敏等潜在损害;以储层敏感性分析为主要方法,借助前期注水状况分析结果,认为引起注入困难的主要原因为水敏、速敏伤害;针对储层损害的主要因素,提出了"有机防膨+无机防膨"的注入水改善措施。
This paper is aimed at presenting the results of our analy- sis of the reservoir lithology, physical property and the clay mineral characteristic features of the reservoir damage caused by the water in- jection of Moliqing Oilfield in Yitong Basin due to the low porosity and low permeability of the local geofeatures. It is based on the de- mands of the reservoir damage evaluation of the reservoir that we have carried out exploration of the likely improvement measures through water injection. The research findings help us to conclude that the reservoir under study should be categorized into the geological types of low porosity and low permeability, with the clay minerals mainly mixed with illite-smectite and kaolin zones. The above mentioned ge- ological features are prone to cause swelling expansion and migration of the clay minerals and lead to pore throat blockage due to the poten- tial water sensitivity, the velocity sensitivity risks in the water injec- tion development, Furthermore, the water sensitivity analysis can also help conclude that such sensitivity damages of such blocks should also be categorized into weak velocity damage, medium-strong water sen- sitivity damage and alkali sensitivity damage, with no acid sensitivity damage in general. According to the results of the comprehensive analysis of the water quality, water injection volume and compatibility of the water characteristic features in the early stage in the oilfield, it can be found that such blockage of injection can be greatly different in the water quality between the water newly injected and formation water, which may result in a relatively great compatibility on the whole and relatively great water injection volume. Based on the afore- mentioned analysis, the chief reasons leading to difficult water injec- tion are due to the irregularity of the water-quality sensitivity and the water flow velocity sensitivity. In accordance with the above damage characteristics and key factors of the sensitivity damages, it can be deduced that the chief influential parameters and the chief character- istic swelling inhibitors in existence to be overcome at present are： it is necessary to analyze the swelling mechanism of the swelling in- hibitors of NaC1 and KC1 inorganic salts through laboratory experi- ments and field tests. Therefore, we have proposed that it is of pri- mary importance to adopt the measures for improving water injection through further improvement of the water properties and cost-reducing measures in an integrated way and joining organic swelling prevention with the inorganic swelling prevention, plus the effective control of the alkaline damage by reducing the Ph value of the working fluid.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2016年第1期10-14,共5页
Journal of Safety and Environment
关键词
安全工程
低孔低渗油藏
注水开发
敏感性
储层损害
防膨措施
safety engineering
reservoirs with low porosity and lowpermeability
water flooding development
sensibility
reservoir damage
swelling control measures
