川东南深层页岩气分段压裂技术的突破与认识

发布时间：2018-03-04 05:17

本文选题：四川盆地东南部　切入点：页岩气　出处：《天然气工业》2016年01期 　论文类型：期刊论文

【摘要】：四川盆地东南部深层(垂深超过2 800 m)页岩气藏受地质背景和成岩作用的影响,储层矿物成分及孔隙结构特征复杂多变,岩石塑性与非线性破裂特征明显增强,最大与最小主应力差异绝对值加大,导致分段压裂施工破裂压力与延伸压力高、裂缝宽度小、砂液比与裂缝导流能力低、体积裂缝难以形成,严重影响了压后页岩气的产能。基于对深层岩石力学性质、地应力特征、破裂特征及裂缝形态特征的分析研究,提出了"预处理酸+胶液+滑溜水+胶液"混合压裂施工新模式及配套技术。现场应用效果表明:丁页2HF井下志留统龙马溪组压后获得页岩气无阻流量10.5×10~4 m~3/d,取得了地质突破;金页1HF井下寒武统{;竹寺组压后获得页岩气无阻流量10.5×10~4 m~3/d,有望获得商业突破。结论认为:①深层页岩复杂缝难以形成,其压裂技术应有别于中深层;②所建立的破裂压力模型可为深层破裂压力的预测提供有效手段;③降低施工压力是确保深层压裂施工安全的关键之一;④深层页岩压裂除了储层应具有良好的物质基础外,增加压裂裂缝复杂性与形成高导流裂缝也非常关键。
[Abstract]:The deep shale gas reservoir in the southeast of Sichuan Basin is influenced by geological background and diagenesis. The mineral composition and pore structure of the reservoir are complex and changeable, and the characteristics of rock plasticity and nonlinear fracture are obviously enhanced. The difference between maximum and minimum principal stress increases in absolute value, which results in high fracture pressure and extension pressure, small fracture width, low sand / liquid ratio and fracture conductivity, and difficult formation of volume fracture. Based on the analysis of the mechanical properties of deep rock, the characteristics of in-situ stress, the characteristics of fracture and the characteristics of fracture morphology, the productivity of shale gas after compression is seriously affected. This paper puts forward a new mode of mixed fracturing operation of "pre-treated acid glue slippery water glue" and its matching technology. The field application results show that the unhindered flow rate of shale gas is 10.5 脳 10 ~ (4) m ~ (4) m ~ (-1) / d after pressure of Silurian Longmaxi formation in Dingpie2HF downhole, and a geological breakthrough has been achieved. Jinping1HF downhole Cambrian {; Zhusi formation obtained a shale gas flow rate of 10.5 脳 10 ~ 4 mm ~ 3 / d after compression, which is expected to make a commercial breakthrough. It is concluded that it is difficult to form complex fractures in the deep shale of the "Wang 1" formation. The fracturing technology should be different from the fracture pressure model established in the middle and deep layers, which can provide an effective method for predicting the deep fracture pressure. Reducing the operation pressure is one of the keys to ensure the safety of deep fracturing operation. In addition to the reservoir should have a good material base, It is also very important to increase the complexity of fracturing fractures and form high conductivity fractures.
【作者单位】：中国石油化工股份有限公司石油工程技术研究院;
【基金】：中国石化科技攻关项目“涪陵区块页岩气层改造优化设计研究”(编号:P14091)
【分类号】：TE357

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