| 摘要: |
| 目的 针对鄂尔多斯盆地南区延长组长6致密砂岩油藏前期常规改造未获得有效突破,单井产量提高不明显的问题,探索复杂缝网体积压裂技术对区块致密油藏的改造效果。方法 基于储层地质特征及岩石力学参数,评价了长6储层脆性指数及体积压裂可行性。分析了近井压裂裂缝起裂压力、起裂方位,明确了逼近角和水平应力差两个因素对远井压裂裂缝遇到天然裂缝的延伸规律。模拟研究了压裂设计参数对压裂裂缝形态及改造体积的影响,并优化了压裂设计参数。结果 优化后的压裂设计关键参数为压裂规模为1 000 m3、设计排量为8.0～10.0 m3/min、滑溜水前置液比例为30%、加砂强度为13%～15%,在此条件下更易获得最优储层改造体积和较高的导流能力。结论 提出了适用于研究区块长6致密砂岩油藏复杂缝网体积压裂适应性评价和体积压裂设计参数优化方法,为复杂缝网体积压裂技术的应用提供了理论依据和现场指导建议。 |
| 关键词: 致密油藏 复杂缝网 体积压裂 脆性指数 裂缝起裂 裂缝优化 |
| DOI：10.3969/j.issn.1007-3426.2023.02.013 |
| 分类号: |
| 基金项目:国家自然科学基金“超深裂缝地层溢流多相流动机理及气体侵入类型识别研究”(52274001)、“高温高压气井环空压力动态预测及安全评价研究”(52074018)联合资助 |
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| Adaptive evaluation and optimization of volumetric fracturing parameters in tight sandstone reservoirs |
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Kong Xiangwei1,2, Wan Xiong1, Guo Zhaoyue1, Zeng Zhihao3, Xu Hongxing4
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1. School of Petroleum Engineering, Yangtze University, Wuhan, Hubei, China;2. Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering (Yangtze University), Wuhan, Hubei, China;3.Research Institute of Engineering Technology, PetroChina Southwest Oil & Gasfield Company, Chengdu, Sichuan, China;4. CCDC Changqing Down Hole Technology Company, Xi'an, Shaanxi, China
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| Abstract: |
| Objective In view of the lack of effective breakthrough in the early stage for conventional reconstruction of Chang 6 tight sandstone reservoir in the southern area of Ordos Basin, the production of a single well was not significantly improved, then the complex fracture network volume fracturing technology was explored to improve the effect of tight reservoir reconstruction in the block. Methods Based on the geological characteristics of the reservoir and the rock mechanics parameters, the brittle index and volumetric fracturing feasibility of Chang 6 reservoir were evaluated. The onset pressure and orientation of near-well fracture were analyzed. The expansion law for the two factors of proximity angle and horizontal stress difference on far-well fracture that encounter natural fracture was defined. The impacts of fracturing design parameters on fracture morphology and volume were simulated and optimized. Results The key parameters of the optimized fracturing design are as follows:the fracture scale is 1 000 m3, the designed discharge rate is 8.0-10.0 m3/min, the proportion of slick water pre-fluid is 30%, and the sanding strength is 13%-15%. It is easier to obtain the optimal reservoir reconstruction volume and higher conductivity under the conditions. Conclusion sAdaptive method is proposed for evaluating and optimizing volumetric fracturing design parameters for complex fracture network in Chang 6 tight sandstone reservoir, which provides theoretical basis and on-the-ground guidance for the application of complex fracture network volumetric fracturing techniques. |
| Key words: tight oil reservoir complex fracture network volume fracturing brittleness index fracture initiation fracture optimization |
