【作者】 崔杰；

【导师】 蒋有录；

【作者基本信息】 中国石油大学 ， 地质资源与地质工程， 2010， 博士

【摘要】 川东北复杂勘探区,由于受多期构造运动影响,造成了深部地层致密碳酸盐岩高压,直接关系到钻井、人身、财产安全,致使勘探难度增大。围绕着川东北地区深部碳酸盐岩地层孔隙压力计算这个难题,本文综合利用地质、地球物理、分析化验、测试等资料,应用石油地质理论、钻井工程技术为指导,从地质模型建立、压力分布特征、气藏特征、孔隙及裂缝气藏压力成因机制、压力预测及现场监测等几个方面,对川东北普光和毛坝地区的压力机制进行了系统分析和定量计算。通过开展压力背景下的地质建模及沉积相模型与地层压力分布关系的研究,认为海相碳酸盐岩地层中受沉积相带控制的特殊储集层的发育,对压力分布具有重要的影响;区分了孔隙型气藏、裂缝性气藏的不同压力特征,台地边缘礁滩孔隙性气藏多为“常压”特征;陆棚、开阔台地等相区多发育裂缝型气藏,呈“超压”特征;利用地质手段,对研究区进行了压力计算模拟,建立了压力的三维空间分布,模拟结果与实测压力数据相比,趋势吻合。碳酸盐岩异常高压形成机制复杂,地层压力是由烃类裂解、构造挤压作用造成的应力累计为主,因沉积背景、岩石类型和物理性质的差异、热化学硫酸盐还原作用(TSR)的不同,等多种作用叠加控制了现今压力特征。研究认为原油裂解成天然气使该地区地层古压力明显增大,形成超压;具体到普光地区,存在TSR反应、构造抬升等泄压机制从而形成常压;而毛坝地区高压、超高压是由于该地区在晚燕山期和喜山期遭受强烈的构造作用,加之储层主要发育为裂缝性灰岩(白云岩),由于裂缝受压的自封闭性特点导致超压很难泄载,这是造成毛坝地区深部储层超压的主要因素。通过对沉积背景和异常压力的成因分析基础上,认为有效应力能反映碳酸盐岩地层孔隙压力变化情况。基于横波速度对地层是否含气的敏感性,建立了纵横波速比和有效应力的指数关系,对建立适用于深部碳酸盐岩孔隙压力预测计算方法进行了有益的探讨。未探明地质条件下的深部地层,因受地震资料分辨率影响,压力预测结果往往不能满足工程应用,因此压力的随钻监测尤为重要。本文提出的地层压力随钻监测新方法的理论基础是机械钻速方程,该方程是依据岩石破碎比能的概念和岩石可钻性级值的定义,结合室内实验条件数据,考虑钻头有效嘴水功率和压差对机械钻速影响建立的。更多还原

【Abstract】 In complex exploration area in Northeast,due to multi-tectonic movement,resulted in deep dense carbonate rock strata exists high pressure,it is directly related to drilling, personal and property security, resulting in exploration difficult. To solve the problem of deep carbonate formation pore pressure calculation in northeast region, integrated with geological, geophysical, analysis and test, using petroleum geology, drilling technology guidance, studying on the geological model, the pressure distribution gas reservoir characteristics, pore and crack formation mechanism of gas reservoir pressure, pressure prediction, and on-site monitoring ,we do a system analysis and a quantitative analysis on pressure mechanism in Puguang and Mao dam area of the Northeast Sichuan .Study the geological modeling under the background of pressure,discuss the relationship between sedimentation model and distribution of formation pressure: it is considered that the development of special reservoir strata controlled by sedimentary facies from marine carbonate formation has an important effect on the distribution of pressure,the paper has distinguished the different characteristics of pressure between porous gas pools and fractured gas pools. Porous gas pools of platform edge shallow facies show the“normal pressure”, continental shelf and open platform have mainly developed in fractured gas pools ,and show“excess pressure”. Using the methods of geology ,computer simulation for the pressure in the study area, establish a three-dimensional space distribution of stress, and the simulation results compared with the measured pressure data, the trend consistent.The formation mechanism of Carbonatite’s overpressure is very complicated. Strata pressure is caused by hydrocarbon cracking and tectonic compression that is mainly cumulative stress. Because of depositional setting, rock types, and different physical characteristics and effect of thermo chemical sulfate reduction(TSR), variety of roles mix to control today’s pressure characteristics.It has studied that crude oil cracked gas to increase strata pressure obviously and caused high pressure. Specific to the puguang area, existing pressure relief mechanism such as thermochemical sulfate reduction, tectonic uplift and so on , Thus forming atmospheric pressure. While high pressure and overpressure is caused by strong tectonic compression in late stage of Yanshan and Himalayan in Mao dam area,and reservoir mainly developed for the fractured reservoir limestone (dolomite) , because of strong self-enclosed of fracture,overpressure will not release easily,so this is the main factor which caused high pressure of deep reservoir in mao dam area.On the base of sedimentary background and causes of abnormal pressure analysis, it is known that the effective stress is able to reflect the changes of carbonate formation rock pore pressure. This depends on Vertical and horizontal velocity ratio and effective stress of high-index, and we do a helpful discuss related to design procedure for deep pore pressure prediction.Deep stratum of not-proven formation conditions pressure calculation result often cannot meet the engineering application due to seismic resolution , so the pressure with monitor drilling is particularly important.In this paper , the equation is based on the concept of broken rock and definition of rock drillability value, combined with the level of indoor experiment data and considering influnce of the effective mouth power of the bit and differential pressure on the penetration rate.更多还原