致密砂岩气藏水平井细分段适应性分析

发布时间：2018-03-20 14:40

本文选题：致密砂岩气藏　切入点：细分段　出处：《天然气地球科学》2017年03期 　论文类型：期刊论文

【摘要】：水平井分段压裂是致密砂岩气藏开发的有效手段,数值模拟表明,缩短缝间距,可以大幅度降低油气流动压差,从而提高单井产量。随着储层品质变差,川西沙溪庙组气藏常规分段(缝间距80~100m)效果变差,采出程度低。在地层压力不同的区域,采用自主研制的不动管柱不限级数滑套分段工具,试验了水平井细分段、拟体积压裂改造。不动管柱分段数最多达到20段,平均段间距为46.3m,平均入地液量为2 775.6m~3。压后对比表明,高压气藏压裂效果好,生产相同时间,较常规分段井累计产量高,稳产好;但常压气藏压后压力降落快,返排困难,压后效果差。对此,结合岩心伤害实验分析了常压气藏压后效果差的原因,认为长时间、大液量施工,对储层渗透率伤害大,同时常压储层地层能量低,滤失到储层的液体难以返出,是导致该类气藏细分段、拟体积压裂返排困难,压后效果差的主要原因。建议致密砂岩常压气藏,不采用水平井细分段、大规模拟体积压裂改造;高压气藏可以推广应用。研究为类似气藏开发提供了借鉴。
[Abstract]:Horizontal well fracturing is an effective method for the development of tight sandstone gas reservoir. Numerical simulation shows that shortening fracture spacing can greatly reduce the pressure difference of oil and gas flow and thus increase the production rate of single well. In Shaximiao formation gas reservoir in western Sichuan, the effect of conventional section (80 ~ 100m apart from fracture spacing) becomes worse and the degree of recovery is low. In the area of different formation pressure, the subdivision of horizontal well is tested by using the self-developed non-moving pipe string open-ended series sliding casing subdivision tool. Pseudo volume fracturing. The maximum number of sections of fixed pipe string is 20, the average interval is 46.3 m, and the average amount of fluid entering the ground is 2775.6 mm3. The comparison after compression shows that the fracturing effect of high pressure gas reservoir is good, and the cumulative production of the same production time is higher than that of conventional segmented well. The steady production is good, but the pressure falls quickly after the atmospheric pressure gas reservoir, the backflow is difficult, the pressure effect is poor. In this paper, the reason of the bad pressure effect of the atmospheric pressure gas reservoir is analyzed in combination with the core damage experiment, and it is considered that the long time and the large amount of liquid construction will cause great damage to the reservoir permeability. At the same time, the low formation energy in the atmospheric pressure reservoir and the difficulty of returning the fluid lost to the reservoir are the main reasons leading to the subdivision of the gas reservoir, the difficulty of the pseudo-volume fracturing and the poor effect after the pressure. It is suggested that the tight sandstone gas reservoir under atmospheric pressure should be formed. Large scale pseudo-volume fracturing is not used for horizontal well subdivision, and high pressure gas reservoir can be popularized and applied. The research provides a reference for the development of similar gas reservoirs.
【作者单位】：中国石化西南油气分公司工程技术研究院;
【基金】：国家科技重大专项“大型油气田及煤层气开发”(编号:2016ZX05048)下设专题“薄层窄河道致密砂岩气藏水平井压裂关键技术”(编号:2016ZX05048004-003)资助
【分类号】：TE37

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