裂缝网络地层钻井液漏失模拟

发布时间：2018-08-04 15:40

【摘要】：针对复杂裂缝性地层的钻井液漏失问题,基于蒙特卡罗随机建模理论,构建了三维离散裂缝网络地层模型。采用宾汉模式钻井液,建立了考虑裂缝线性变形的裂缝网络地层钻井液漏失模型,并利用有限元法求解该模型,对钻井液漏失行为进行模拟。研究表明,该模型可以进行裂缝内流速、漏失速率及漏失量等动态模拟;近井筒附近裂缝内钻井液流速较高,远离井筒处裂缝内流速较低;经过对数变换后,钻井液漏失速率曲线具有明显的无规律波动现象,与单条裂缝的漏失存在明显区别,可以用于识别裂缝网络地层;裂缝应力敏感性对漏失影响较大,考虑应力敏感性后,钻井液漏失量增加;数值模拟得到的漏失量与理论漏失量十分接近,证实模型可靠度高。现场应用表明,研究成果可有效识别出裂缝网络漏失,并以此采取了合理的堵漏技术方案,堵漏一次成功。
[Abstract]:Aiming at the problem of drilling fluid leakage in complex fractured formations, a three-dimensional discrete fracture network formation model is constructed based on Monte Carlo stochastic modeling theory. Based on the Bingham drilling fluid, the model of drilling fluid loss in fractured network formation considering linear deformation of fracture is established. The model is solved by finite element method, and the leakage behavior of drilling fluid is simulated. The results show that the model can be used to simulate the flow velocity, leakage rate and leakage rate of the fracture, the velocity of drilling fluid near the wellbore is higher, and the velocity is lower in the fracture far from the wellbore. After logarithmic transformation, the flow rate of the drilling fluid in the fracture near the wellbore is lower than that in the borehole. The leakage rate curve of drilling fluid has obvious irregular fluctuation phenomenon, which is obviously different from the leakage of single fracture, and can be used to identify the fracture network formation, the stress sensitivity of fracture has a great influence on the leakage, and considering the stress sensitivity, the leakage rate of drilling fluid is different from that of single fracture, and it can be used to identify the formation of fracture network. The loss of drilling fluid is increased and the leakage obtained by numerical simulation is very close to the theoretical loss, which proves that the reliability of the model is high. The field application shows that the research results can effectively identify the leakage of the fracture network and adopt a reasonable scheme of plugging technology, and the plugging is successful once.
【作者单位】：中国石化石油工程技术研究院;页岩油气富集机理与有效开发国家重点实验室;西南石油大学·油气藏地质及开发工程国家重点实验室;
【基金】：国家科技重大专项(2011ZX5005-006) 国家自然科学基金重大项目(51490650)资助
【分类号】：TE254

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