发展注气提高采收率技术

提高采收率(EOR或IOR)研究是油气田开发永恒的主题之一。当今世界,蒸汽驱仍占主导地位。近几年由于油价低,化学驱下降,而注气驱则连续增加。中国东部油田的储层属陆相沉积,非均质严重,原油粘度又比较高,含水上升很快,水驱采收率比较低,约33%。近期发现的石油储量又多属低渗透及高粘度等难采储量,发展提高采收率技术已成为陆上石油工业继续发展的一项迫切战略任务。1998年,全国开展了三次采油潜力的二次评价工作,据初步统计,适合于注气(CO2)混相驱的地质储量在10.57×108t以上。综合研究国外经验,结合我国三采潜力分析和评价,认为目前我国东部油区有条件的油田要侧重发展注非烃气驱,而西部则侧重发展注烃气驱技术。发展非烃气驱的关键在气源,要重视寻找天然CO2气源。探索发展制N2、注N2、脱N2和制CO2等技术。注意发展国产的压缩机装备。抓好注气驱先导试验和富含凝析油的凝析气藏回注干气的试验。加强注气提高采收率的理论和实验研究,作好技术储备,培养好人才。

STREATHEN GAS INJECTION FOR ENHANCED OIL RE COVERY

Enhance Oil Recovery (EOR)is one of the permanent top-ics in research on Oil/gas reservoir development. Because of low oil price, the demand for chemical drive is keeping decreasing and for gas drives increasing. The reservoirs in East China oil fields are non-marine deposits with Serious heterogeneity and high viscosity crudes, Water Cut increases very fast, recovery by water drive is relatively low, only 33%.The reserve discov-ered recently is difficult to produce because of low permeability of the reservoirs and high viscosity of the crudes, streathening gas injection for enhanced oil recovery has become an urgent strategy in on shore petroleum industry development. China launched the evaluation in the second time on tertiary recovery potential in 1998.By statistics, the geological reserve suitablefor gas injection(CO2) miscible flooding is over 10.57×108 tons. By combination of foreign experience and the analysis and evaluation on China’s tertiary recovery potential, it is recog-nized that the oil fields in east china oil- bearing provinces should streathen non-gas drive and the oil field in west china should be hydrocarbon drive dominant. The key to gas drive isgas resource, the discovery of CO2resource should be placed at-tention to, and the technology to generate N2and CO2, inject and sperate N2should be probed. The development of compres-sion facility-home made, pilot tests of gas drive and dry gas recycle for gas condensate reservoir with rich condensates should be speeded up.