油田注水配注合理注采比计算方法研究

为了稳定油藏原油产量、控制含水上升速度,需要确定油藏在注水开发过程中的合理配注量或注采比。通过应用油藏工程方法中广泛使用的经验公式和理论公式推导出了新的注采比随含水率变化预测模型。该模型直观表达了油田累积产油量与含水率关系及油田注采比随含水率变化的关系,其特点在于给定未来某一时刻油田含水率,就能确定其合理注采比。通过实例计算表明,应用该关系式计算结果可靠,参数获取简便,可用于指导生产静动态参数录取较少的区块油藏进行配注计算。

异常高压特低渗透油藏试井分析及应用

近年来,准噶尔盆地环玛湖地区相继发现了多个异常高压特低渗透油藏,由于该类油藏存在孔喉细小、比表面积大、渗透率低、压敏性强的特点,渗流规律不遵循达西定律。为做好该区此类油藏的开发工作,以该区已经投入开发的玛2井区为例,在研究总结异常高压、特低渗透砂砾岩储层地质特征的基础上,分析历史不稳定试井曲线,确定该区油藏渗流遵循低速非达西渗流规律。以低速非达西渗流理论为基础,建立考虑启动压力梯度的低速非达西渗流试井解释模型。通过对实际测试资料的解释分析,获得真实的油层参数,确定了生产井的启动压力梯度大小及合理关测时间,评价了油井完善程度,对异常高压、特低渗透砂砾岩油藏的合理开发提供了可靠的依据。

改善百21井区砾岩油藏高含水期开发效果的实践与认识

针对百21井区砾岩油藏水驱失控造成的生产形势恶化的问题,在深化注水窜流优势通道及分类砂体研究基础上,平面上更新、补钻注水井、老井转注,完善井网提高水驱控制程度,分区域、分相带精细注水调控;剖面上砂体组合分注、配合调剖调驱,提高剖面动用程度,分砂体精细注水调控;精细管理提高配注合格率保障注水质量。治理后开发效果明显改善,绝对油量递减减缓7.2%,含水上升率下降1.2%,恢复采收率2.8%,恢复可采储量179.8万t。

Applying the Dynamic Two-Step Method to Forecast Remaining Oil Distribution of Lower Series ,Xiaermen Oilfield

The distribution of remaining oil is often described qualitatively. The remaining oil distributed in the whole reservoir is calculated according to the characteristics of the space distribution of the saturation of remaining oil. Logging data are required to accomplish this. However, many such projects cannot be completed. Since the old study of remaining oil distribution could not be quantified efficiently, the ＂dynamic two-step method＂ is presented. Firstly, the water cut of every flow unit in one well at one time is calculated according to the comprehensive water cut of a single well at one time. Secondly, the remaining oil saturation of the flow unit of the well at one time is calculated based on the water cut of the flow unit at a given time. The results show that ＂dynamic two-step method＂ has characteristics of simplicity and convenience, and is especially suitable for the study of remaining oil distribution at high water-cut stage. The distribution of remaining oil presented banding and potato form, remaining oil was relatively concentrated in faultage neighborhood and imperfect well netting position, and the net thickness of the place was great. This proposal can provide an effective way to forecast remaining oil distribution and enhance oil recovery, especially applied at the high water-cut stage.

玛湖凹陷北斜坡百口泉组层序地层格架

玛湖凹陷北斜坡百口泉组油藏开发过程中油水分布规律复杂,开发过程中开发层系划分和储层砂体对比存在诸多矛盾。以岩心、测井、地震资料为基础,以层序地层学理论为指导,结合地震剖面反射特征开展三叠系百口泉组层序地层划分和对比,并建立统一层序地层格架,为油藏开发层系划分和储层砂体对比提供依据。玛北地区百口泉组划分为1个长期基准面旋回,呈现为基准面上升及湖侵的特征;可进一步细分为MSC1、MSC2、MSC3等3个中期旋回,其中MSC2旋回厚度最大,为最有利含油层段,垂向上多层含油,T1b22、T1b21为主力油层。玛北地区百口泉组层序发育与演化明显受控于构造作用,自盆地边缘向盆地方向存在外坡折、中坡折和内坡折三个坡折带。通过建立统一的三叠系百口泉组层序地层格架为油藏开发层系划分和储层砂体对比提供依据,指导剩余油挖潜和加密井部署。

准噶尔盆地玛湖西北地区M井区三叠系克上组构造特征研究

M井区区域构造位于准噶尔盆地西北缘克—乌断阶带下盘东北段。克下组储层在克—乌断裂东侧自北西向南东方向呈单斜式倾斜,倾角5°~10°,断裂西侧附近受逆牵引作用可达30°;自西北向东南方向单斜展布,构造埋深-1550m^-1760m。各沉积单元顶面构造与克下组顶面构造具有一致性,西北向东南单斜展布,局部具有微幅度差异。M井区断裂发育主要有三期,即海西运动期、燕山运动期和喜马拉雅运动期;断裂的展布具有明显的方向性,其中以北东向和北西向占主导。百口泉断裂为逆冲断裂,断裂活动早期为石炭纪末期,定型于三叠系,结束于侏罗纪中期,是海西、印支、燕山活动产生的。

准噶尔盆地玛北隆起带玛2井区石油地质特征

玛北隆起带油气资源丰富,已探明石油地质储量1.2亿吨。探明面积外油气显示丰富,滚动勘探潜力巨大。为落实资源规模,近年来针对已探明油藏周边及探明层系上下邻层开展了高分辨率层序地层学研究、构造精细解释、沉积相精细刻画、多方法优势储层预测等工作,明确了二叠系油藏沿尖灭线分布、三叠系油藏“阶梯式”递进分布的平面展布规律,落实了找油方向。同时结合动、静态资料开展单井潜力摸排、恢复试油、评价部署、开发实验等工作,先后发现了三叠系、二叠系等多个油藏,落实储量资源近亿吨。

百21井区三叠系白碱滩组构造特征

百口泉油田位于准噶尔盆地西北缘克—乌断裂带百口泉段。该区白碱滩组顶面构造形态为一西北向东南缓倾的单斜。在三条大型逆掩断裂的控制下,区内发育多条小断裂,北部多发育北西—南东向断裂,断距较小,与构造上倾方向逆断裂组合成多个断块圈闭;南部多发育近东西向断裂,断距相对较大。克—乌断裂在本区为近南北走向的逆断层,资料范围内延伸长度3.8 km,倾向正西。剖面上断裂上陡下缓,倾角30°~70°,目的层最大断距100 m,断开层位为石炭系、二叠系、三叠系和侏罗系。