稠油油藏松散岩心分析方法的评价

AN EVALUATION OF THE CORE ANALYSIS TECHNIQUE OF UNCONSOLIDATED CORES FROM A HEAVY OIL RESERVOIR

本文系笔者对加拿大GEOTECH公司实验室稠油松散岩心分析方法所进行的简要评价,目的是希望对其分析结果的可信程度有一个正确的认识。保护松散岩心最可行的措施是采用硬塑料取心衬管,用干冰冷冻岩心并用热缩性塑料套和不锈钢丝网包封岩心样品。要想尽可能保持岩心的原始状态,取心及选样的每个步骤都要格外仔细。松散岩心样品必须在相当于地层上覆压力的围压条件下试验,才能获得有代表性的结果,但要确定地层原始的孔喉结构是很困难的。稠油松散岩心在高压高温下进行驱替试验时,很可能因微粒移动受到影响。

This paper gives a brief description and the evaluation of the test procedures for unconsolidated cores from heavy oil reservoir in Geotech's lab. in Canada, in order to have a proper understanding on realiability of the testresults. The most practical measures for protecting unconsolidated cores are using hard plastic coring linel, freezing cores with dry ice and wrapping up core plugs in thermal shrinking sleeves and stainless steel screens. But special care must be taken to keep the sample in original state as far as possible. In order to get representative data, unconsolidated core sample should be tested under a confining pressure equal to formation overburden pressure. However, it's too difficult to determine original pore and throat size in formation. Flooding test for unconsolidated core sample with heavy oil at high temperature and pressure may be impacted by movement of the fines.