摘要
库车前陆盆地裂缝性致密砂岩储层具有超深超高压的特点,通过适当的改造策略,尽可能地激发天然裂缝的潜能是获得经济效益产能的关键。提出在精细储层裂缝评价和测井解释的基础上,进行天然裂缝的力学活动性研究,优选储层改造工艺。通过数值模拟和理论推导,指出除裂缝的倾角倾向以外,天然裂缝的有效性对其在改造中的力学活动性有明显的影响,并给出裂缝的剪切激活压力的计算方法;从钻井液漏失事件、成像测井参数定量分析、岩心分析、R/S变尺度分析等方面进行裂缝有效性的综合评价,提出了适合此类储层裂缝分类标准;根据天然裂缝力学活动性的分析结果,提出了有针对性的改造策略,即对3种不同裂缝发育特征的储层,可以分别优先采用体积酸压、缝网压裂和大规模加砂压裂等不同压裂改造策略。以此方法改良的储层改造方案,在库车西部博孜区块的实际井施工获得了理想效果,改造后产量较邻井提升显著,为该地区近千亿立方米储量的有效动用提供了理论依据和技术支持。
The fractured tight sandstone reservoir in the Kuqa foreland basin is ultra-deep with ultra-high pressure. To obtain economic productivity from the reservoir, it is essential to stimulate the potential of natural fractures with appropriate strategy. Based on the fine fracture evaluation and logging interpretation, the mechanical activity of natural fractures is studied, and accordingly the reservoir stimulation treatment is optimized. Through numerical simulation and theoretical analysis, it is found that the effectiveness of natural fractures, in addition to the dip angle and dip direction, has a significant effect on the mechanical activity of fractures during the treatment, and the calculation method of the shear activation pressure of the fracture is given. The effectiveness of fractures is evaluated comprehensively in respect of mud loss events, quantitative analysis of imaging logging parameters, core analysis, R/S scale-variable analysis and so on, and the classification criteria for such reservoir fractures is put forward. According to the analysis on mechanical activity of natural fractures, the customized stimulation strategies are proposed. To be specific, different fracturing strategies, such as volumetric acid fracturing, fracture network fracturing and large-scale sand fracturing, can be employed for three types of reservoirs with different fracture development features. In this way, the reservoir stimulation scheme is improved. The improved scheme has been satisfactorily applied in the Bozi block in the western Kuqa basin. As a result, the actual production is significantly higher compared with adjacent wells. This scheme facilitates theoretically and technically the effective production of nearly 100 billion cubic meters of reserves in the block.
出处
《中国石油勘探》
CAS
北大核心
2017年第6期47-58,共12页
China Petroleum Exploration
基金
国家科技重大专项"大型油气田及煤层开发"(2016ZX05051-003)
关键词
一体化方法
裂缝有效性
裂缝力学活动性
压裂策略
博孜区块
integration method, fracture effectiveness, mechanical activity, fracturing strategy, Bozhi block
