【作者】 李海波；

【导师】 陈德春；

【作者基本信息】 中国石油大学 ， 油气田开发工程， 2011， 硕士

【摘要】 目前石油工业正面临后备储量紧张及探明未动用石油储量中低渗透储量占很大比例等问题。为有效动用低渗透油田的储量,各种油气层增产技术发挥着重要的作用。其中油气层爆燃压裂技术效果良好,但对其影响因素、裂缝延伸过程中动态分析以及目的层裂缝条数与效果的预测缺乏研究,影响其技术发展。本文基于固体药柱燃烧分析、火药的燃速方程、质量、能量守恒方程及爆燃产物状态方程,结合井筒爆燃压裂的边界条件,建立了密闭条件下油气层爆燃压裂加载数学模型。研究火药爆燃过程中P-t、T-t关系曲线及不同初始压力、装药质量、内外径、初始空间体积对P - t、T-t曲线的影响;基于油气层爆燃压裂加载模型,研究了地层破裂、止裂压力计算模型、爆燃气体渗滤计算模型、裂缝延伸长度、宽度和裂缝体积计算模型以及爆燃气体的质量和能量守恒计算模型,建立了火药爆燃加载-地层开裂-裂缝延伸的爆燃压裂裂缝动态延伸模拟的耦合动力学模型,分析了爆燃压裂过程中井筒压力、温度变化规律、裂缝几何形态变化规律,编制了计算软件,并进行耦合求解。研究结果表明,火药爆燃后,井筒中的压力、温度迅速上升,达到地层破裂压力时起裂,裂缝开始延伸;在火药爆燃、气体渗滤作用下,爆燃气体的压力先增加后减小直到降为地层初始压力。在爆燃加载条件相同的情况下,峰值压力的大小随裂缝条数的增加而降低,裂缝长度随裂缝条数的增加而减小;裂缝宽度随着压力的变化先增大后减小,裂缝条数越少裂缝宽度最大值和裂缝宽度的最终值越大。根据裂缝延伸模型绘制不同裂缝条数的P - t曲线,结合现场实测P - t变化曲线,通过曲线相似原理找出与实际曲线最吻合的P - t曲线,从而推测现场爆燃压裂的裂缝开裂情况。包括裂缝条数、裂缝延伸长度、宽度等;运用一级模糊综合评判,结合原有大量岩石冲击开裂实验数据,研究影响其裂缝条数的影响因素,得到各因素的权重,建立其裂缝条数预测模型。设计26组试验得到新的实验数据,验证模型假设的正确性及预测模型的精度。通过爆燃压裂的一系列的研究为其技术工艺参数设计和控制提供了理论依据,对其技术的发展和应用具有重要的现场指导意义。更多还原

【Abstract】 At present the oil industry is facing backup unused tension and proved reserves of low permeability oil reserves accounting for a large proportion problems and so on. To effectively use these difficult reservs, Various hydrocarbon reservoir production technology plays an important role. Among them, the hydrocarbon reservoir exploding fracturing made sewing technology plays a good effectiveness, But for the influence factors、the analysis on the crack extension in the process of dynamic and the purpose of fractures and the number of cracks of objective stratum lack of research influence the technological development. This thesis based on solid medicine column combustion analysis、the explosive exploding equation、quality、energy conservation equation and the exploding production state equation, Combining the boundary condition of wellbore exploding fracturing, Established the loading mathematical model under airtight condition of hydrocarbon reservoir exploding fracturing. Research on the relation curves of P - t、T - t in explosive exploding process and the relation curves of P - t、T - tby the different initial pressure、charging quality、inside and outside diameter, initial sPace volume, Based on the loading model reservoir exploding fracturing,formation cracking, and fractures extending is established after five modes’research including calculation model of formation breakdown pressure and crack arrest pressure,model of exploding gas infiltration, model of fractures extending length and width, and model of exploding gas energy and momentum conservation based on fracture initiation loading model of reservoir exploding fracturing process. The variation law of wellbore pressure and fracture geometry is analyzed. Research results show that: wellbore pressure and temperature rapidly increase after explosive’s exploding and the wellbore pressure causes fracture initiation as well as fracture extension when it reaches formation breakdown pressure; exploding gas’pressure firstly increase and then decrease to formation pressure under the effect of explosive exploding and gas infiltration. Both of the peak pressure and fracture length decrease with fracture numbers increasing; fracture width firstly increases and then decreases with pressure increasing and the fewer the fracture number is, the bigger the fracture maximum width as well as final width are on the same explode loading condition. According to crack extension model draw the different numbers of crack about the P - t curve, Combined with the actual P - t change curves, Through the curve similarity principle to find the most consistent with actual curve of P - tcurve, Thus speculate the site initiation situation of exploding fracturing cracks. Including the number, crack extension crack length, width, etc; Using the method of level 1 fuzzy comprehensive evaluation, combined with the original experimental data of blast cracking of rock. Studying the influence factor of cracks number , Getting the weights of all the factors, Establishing the prediction model of cracks number. Design 26 groups of testing to get a new experimental data, Verifying the correctness of the model hypothesizes and the precision of the predict model. Through a series of research on exploding fracturing technology for the Parameters design and control provides theory basis, and for the technical development and application has important guiding significance in the site.更多还原