延长油田上古生界气藏压裂改造工艺技术分析

延长油田上古生界气藏储层连续性较差、含气砂体变化快、非均质性强,具有典型的低孔、低渗、低压、低丰度、低产的特点,储层压裂改造工艺难度较大。在近几年的天然气勘探过程中,通过不断的研究、试验和现场应用,总结出一套基本适应于本区上古生界气藏石盒子组、山西组、本溪组等储层的压裂改造工艺,现场施工后取得了较好的效果。为此,从射孔工艺、加砂压裂工艺特别是压裂液体系、支撑剂、施工主要参数的确定、压裂配套工艺等多个方面进行了阐述,并对现场的施工情况和室内的研究结果加以分析和佐证,最后对延长油田上古生界气藏的下一步压裂改造工作提出了建议。

An Analysis of Fracturing Reform Technology about Upper Paleozoic Gas Reservoirs in Yanchang Oilfields

The upper paleozoic gas reservoirs in Yanchang Oilfields are characterized by the poor continuity, the rapid change of gasbearing sand-bodies, and the strong uneven property, and possess the typical features of low holes, low permeability, low pressure, low degree of richness and low production, so it is very difficult to apply the fracturing reform technology to the gas reservoirs. In recent years of natural gas exploration, after the continuous researches, tests and field uses, a series of fracturing reform technologies are summarized, which are adaptable to the upper paleozoic gas reservoirs of Shihezi group, Shanxi group, Benxi group and so on in Yanchang region, and thus getting the better effect after the field construction. Therefore, an explanation of fracturing reform technology is conducted from the following aspects like perforation technology, fracturing technology with sand, especially the confirmation of fracturing liquid system, supporting agent and construction main parameters, and fracturing collocation technology. Then, this reform technology has been analyzed and proved by the field construction state and the result of research in the room. Finally, some suggestions are presented aiming at the next step of fracturing reform work about the upper paleozoic gas reservoirs of Yanchang oilfields.