条带状储层压裂水平井复杂多裂缝产能研究

发布时间：2019-02-21 09:35

【摘要】：近年来在鄂尔多斯盆地上古生界、四川盆地须家河组、塔里木盆地库车深层发现了一批大型致密气田,致密气储量、产量均呈现出快速增长趋势,是支撑我国天然气工业快速、健康、稳定发展的生力军。水平井多段压裂是开发致密气的主要有效手段。压裂水平井的产能预测模型是压裂裂缝参数优化的基础。压裂水平井产能模型国内外研究较多,但存在以下两方面的局限。第一是随着压裂改造技术的精细化发展,以往将单条裂缝当做整体建立产能预测模型的处理思路不符合地层下的实际情况,过于简单。应建立沿裂缝缝长方向分段处理的精细化产能模型,并在此基础上建立复杂多裂缝产能适合的预测模型。第二是随着连续均质大砂体储层的枯竭,河道沉积形成的条带状非均质储层成为致密气开发的重要战场,在这类复杂地质条件下建立压裂水平井产能预测模型是亟待解决的难题。故本文在以往压裂水平井产能研究的基础上,从裂缝精细化产能和条带状非均质储层两方面入手进行压裂水平井产能研究。基于点源函数理论,在实空间内通过纽曼乘积原理和势叠加原理建立均质储层内变缝宽裂缝产能预测模型,利用该模型分析了沿裂缝壁面流入量变化规律、楔形裂缝的宽窄程度在不同流动阶段对产能的影响情况。在变缝宽裂缝模型的基础上建立了压裂水平井的多井系统产能预测模型和复杂裂缝系统产能预测模型,分析了多井系统中不同位置裂缝产量的变化规律、复杂裂缝系统中不同位置裂缝产量变化规律等,并提出了沿裂缝缝长方向导流能力优化建议、压裂水平井多井系统以及复杂裂缝系统的裂缝参数优化建议。在均质储层压裂水平井产能预测模型的基础上,结合边界元方法思想,通过拉氏空间内推导盒型封闭边界点源函数解建立了条带状非均质储层压裂水平井产能预测模型。为突出非均质储层为研究重点,将裂缝作为整体考虑。本论文应用此模型分析了非均质储层压裂水平井的水平井筒流入量、裂缝产量变化规律,讨论了非均质储层对井筒及裂缝流入量的影响规律、裂缝对井筒流入量的影响规律、缝间干扰对产量的影响规律等,在此基础上总结出在条带非均质储层中的布缝优化思路并将其运用到实例井中。综上,本论文从裂缝的变缝宽形态和条带状非均质储层这两个方面扩充了压裂水平井产能预测模型,为裂缝参数优化提供了一定指导。
[Abstract]:In recent years, in the Upper Paleozoic of Ordos Basin, a number of large and dense gas fields have been discovered in Xujiahe formation and Kuqa deep layer in Sichuan Basin and Tarim Basin. The dense gas reserves and production have all shown a rapid growth trend, which is the support for the rapid development of natural gas industry in China. Healthy, stable development of the new force. Multi-section fracturing in horizontal wells is the main effective means to develop dense gas. The productivity prediction model of fractured horizontal well is the basis of fracture parameter optimization. There are many researches on fracturing horizontal well productivity model at home and abroad, but there are two limitations in the following aspects. The first is that with the fine development of fracturing technology, it is too simple to treat single fracture as a whole to establish productivity prediction model. A fine productivity model should be established to deal with fracturing along the direction of fracture length, and a prediction model for complex multi-fracture productivity should be established. The second is that with the depletion of the continuous homogeneous large sand reservoir, the banded heterogeneous reservoir formed by the channel deposition becomes an important battlefield for the development of dense gas. It is an urgent problem to establish a productivity prediction model for fractured horizontal wells under such complicated geological conditions. Therefore, based on the previous research on productivity of fractured horizontal wells, the productivity of fracturing horizontal wells is studied from two aspects: fine productivity of fractures and strip heterogeneity reservoirs. Based on point source function theory, the productivity prediction model of variable fracture width fractures in homogeneous reservoir is established by Newman product principle and potential superposition principle in real space, and the variation law of inflow along fracture wall is analyzed by using this model. The influence of the width of wedge-shaped fracture on productivity in different flow stages. On the basis of variable fracture width fracture model, the productivity prediction model of multi-well system and complex fracture system is established, and the variation law of fracture production in different positions in multi-well system is analyzed. The variation law of fracture production in different positions in complex fracture system is presented. The optimization suggestions of flow conductivity along the direction of fracture length, the optimization of fracture parameters of multi-well system of fractured horizontal well and complex fracture system are put forward. Based on the productivity prediction model of fractured horizontal wells in homogeneous reservoirs and the idea of boundary element method, the productivity prediction model of fractured horizontal wells in strip heterogeneous reservoirs is established by deducing the box closed boundary point source function solution in Lagrangian space. In order to focus on heterogeneous reservoirs, fractures are considered as a whole. In this paper, the model is used to analyze the horizontal wellbore inflow and fracture production change of fractured horizontal wells in heterogeneous reservoirs, and to discuss the influence of heterogeneous reservoirs on wellbore and fracture inflow, and the influence of fractures on wellbore inflow. On the basis of the influence of interfault interference on production, the author summarizes the idea of optimizing fracture distribution in strip heterogeneous reservoir and applies it to an example well. In summary, this paper extends the productivity prediction model of fractured horizontal wells from the two aspects of fracture width shape and strip heterogeneity reservoir, and provides some guidance for the optimization of fracture parameters.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357

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