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萨斯喀彻温省的大多数稠油油藏层薄且位于油田边缘,不适宜用热采方法。对这些稠油油藏而言,非混相的CO_2或天然气驱替工艺可能是十分有利的提高原油采收率技术。如果该工艺的确适用,将会采出90%的原始石油地质储量。该地区无廉价的CO_2资源,可用含有CO_2的其它气体代替。本文采用萨斯喀彻温省研究委员会实验室研究结果来评价含85mol%N_2和15mol%CO_2烟道气的适用性,并评价稠油开发的多种开发技术政策。试验所用稠油(14°API比重)是从位于LOYMINSTER地区的SENLAC油藏收集到的。本项评价研究了驱替类型(二次或三次),注入方式(段塞试验及水-气交替驱替),原油类型(SENLAC含气原油与脱气原油),注入气体(烟道气及CO_2)等因素对原油采收率的影响。采用SENLAC油烟道气所做的线性岩心驱替试验(28℃,2.5-2.7MPa实施状态下)得出的主要结论是: 1.在三种不同注入方式(二次段塞、三次段塞及三次水气交替)之中,含气原油采用二次气段塞注入是稠油开发最适宜的注入方式。因为采用这种注气方法具有很高的驱替效率。 2.用三次水气交替方法比二次段塞方法可以采出更多的原油,因为前者的优势在于能够提高对流度的控制。 3.实验中用含气原油比用脱气原油总采收率高。这是由于含气原油的流度相对更为适宜,含气原油实验中操作压力略高一点。 4.烟道气可作为有效驱替介质,因为其原油采收率比采用CO_2仅低2-4个百分点。人们认为用烟道气方法获得的较好原油采收率是二个竞争机制的综合结果——一为由N_2提供的游离气驱机理,另一个由CO_2提供的溶解机理,这不同于CO_2驱占主导的溶解机理(由CO_2提供)。
Most of Saskatchewan’s heavy oil reservoirs are thin and located on the margins of oil fields and are not suitable for thermal recovery. For these heavy oil reservoirs, immiscible CO 2 or natural gas displacement processes may be very advantageous techniques for enhancing oil recovery. If the process is indeed applied, 90% of the original petroleum geological reserves will be recovered. There are no cheap CO 2 resources in the area, which can be replaced by other CO 2 -containing gases. This article uses the Saskatchewan Research Council laboratory results to evaluate the suitability of 85 mol% N 2 and 15 mol% CO 2 flue gases and to evaluate a wide range of development technology policies for heavy oil development. Heavy oil used for the test (14 ° API gravity) was collected from the SENLAC reservoir located in the LOYMINSTER area. In this evaluation, the type of displacement (secondary or tertiary), injection mode (slug test and water-gas displacement), crude oil type (SENLAC gas and crude oil), injected gas (flue gas and CO_2) and other factors on the recovery of crude oil. The main conclusions drawn from the linear core flooding experiment (28 ℃, 2.5-2.7MPa) made by SENLAC flue gas are as follows: 1. In three different injection modes (secondary slug, tertiary slug, Three alternating water and gas), the gas filled with secondary gas slug slug injection is the most suitable injection of heavy oil development. Because of this gas injection method has a high displacement efficiency. 2. Three times more water than gas can be used to produce more crude oil than the secondary slug process because the former has the advantage of being more controllable. 3. The experiment with gas crude oil than the total recovery of high crude oil. This is because the flow of gas-bearing crude oil is relatively more suitable and the operating pressure in the gas-bearing crude oil experiment is slightly higher. 4. Flue gas can be used as an effective displacing medium because its crude oil recovery is only 2-4 percentage points lower than with CO 2. It is believed that better oil recovery by flue gas is the result of two competing mechanisms - one is the free gas drive mechanism provided by N 2 and the other is the dissolution mechanism provided by CO 2, which is different from CO 2 flooding The dominant dissolution mechanism (provided by CO_2).