| 海相页岩缝网可压性靶窗空间分布预测——以川南长宁区块为例 |
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| 引用本文： | 沈骋,赵金洲,谢军,范宇,宋毅.海相页岩缝网可压性靶窗空间分布预测——以川南长宁区块为例[J].地质力学学报,2020,26(6):881-891. |
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| 作者姓名： | 沈骋 赵金洲 谢军 范宇 宋毅 |
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| 作者单位： | 1.中石油西南油气田分公司页岩气研究院, 四川 成都 610051 |
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| 基金项目： | 国家科技重大专项（2016ZX05062）；国家自然科学基金项目（51490653） |
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| 摘 要： | 靶窗的确定对海相页岩气储层增产改造具有重要意义。以川南长宁地区龙马溪组海相页岩气储层为研究对象，开展氩离子抛光扫描电镜、巴西圆盘实验和压裂施工统计，分析矿物颗粒粒径和断裂韧性、地应力对裂缝在水力压裂时能否快速穿透、稳定扩展、充分转向等方面的影响。针对现有方法未充分考虑储层压裂品质的情况，简化计算流程，分别采用声波、密度、伽马和矿物含量等建立脆延性指标，采用优化后的应力与应力差耦合模型建立应力差异指标，形成基于储层缝网可压性理论、根据测井解释曲线形态判别的靶窗预测方法。研究结果表明，脆延性指标和应力差异指标曲线呈现叠合度较高的Ⅰ类双"波谷"的层位最有利于开发，其次为Ⅱ类连续交错叠置的层位，最后为Ⅲ类不连续交错的层位。对长宁地区评价井、建产井的验证与实践表明，靶窗对应的指标多呈现双"波谷"形态，但靶窗对应的层位具有差异，区内自西向东靶窗呈现1小层—2小层—1小层的演化趋势。实现不同井区差异化靶窗的高钻遇率对单井获得较大储层改造规模、较高的测试产量和稳定的累计产量具有重要的控制作用。
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| 关 键 词： | 靶窗预测 脆延性 应力状态 缝网可压性 钻遇率 长宁区块 |
| 收稿时间： | 2020/8/25 0:00:00 |
| 修稿时间： | 2020/10/28 0:00:00 |
Target window spatial distribution prediction based on network fracability: A case study of shale gas reservoirs in the Changning Block, southern Sichuan Basin |
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| SHEN Cheng,ZHAO Jinzhou,XIE Jun,FAN Yu,SONG Yi.Target window spatial distribution prediction based on network fracability: A case study of shale gas reservoirs in the Changning Block, southern Sichuan Basin[J].Journal of Geomechanics,2020,26(6):881-891. |
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| Authors: | SHEN Cheng ZHAO Jinzhou XIE Jun FAN Yu SONG Yi |
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| Institution: | 1.Shale Gas Research Institute, PetroChina Southwest Oil & Gas Field Company, Chengdu 610051, Sichuan, China2.State Key Laboratory of Oil and Gas Reservoir Geology and Exploration, Southwest Petroleum University, Chengdu 610500, Sichuan, China3.China National Petroleum Corporation, Beijing 100007, China |
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| Abstract: | Target window optimization has significance for marine shale gas reservoir stimulation. Taking the marine shale gas reservoir in the Longmaxi Formation of the Changning Block in the southern Sichuan Basin as the research object,argon ion polishing scanning electron microscope,Brazilian disk experiment and fracturing operation statistics were carried out and the influence of mineral size,cracking toughness and crustal stress on hydraulic fracture penetration,propagation and diversion were analyzed. In view of the inadequate fracturing-quality effect of the current methods on the prediction of target window in shale gas reservoir,a new target window prediction method based on the network fracability theory,illustrated by the morphology of logging curves,was established,using brittle-ductile index calculated by sonic,density,gamma and mineral content logging data,and stress difference index calculated by the optimal stress-stress difference coupling model derived from the mechanics theory and experiment in a fast track. The results show that the Ⅰ-type target window,showing a considerable overlap between the curves of brittle-ductile index and stress difference index with "double-trough",is the most favorable for development,followed by the successive cross-overlap as the Ⅱ-type and the discontinuous cross as the Ⅲ-type. The application in the Changning Block shows that most of target windows in each well have the "double-trough" shape,but the corresponding layer of each target window is different. The target windows from west to east have changed from the 1 layer to the 2 layer and then back to the 1 layer. The high drilling-encounter rate of various target windows in different well-controlled zone positively controlled the stimulation reservoir volume,test productivity and cumulative productivity. |
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| Keywords: | target window prediction brittle-ductile property stress state network fracability drilling-encounter rate Changning Block |
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