大庆油田属于非均质砂岩油田，随着开采时间的延长和含水率的上升，油水分布关 系日趋复杂，纵向上多层见水、多层高含水的现象越来越普遍，剩余油分布越来越零散， 剩余油挖潜越来越难。如何实现经济有效的加密调整，改善开发效果，弥补产量递减趋 势，越来越引起油田的重视。萨南开发区四—八区属于三角洲内、外前缘相沉积，特别 是对薄油层和表外层，作为三次加密调整的对象，基本以外前缘相沉积为主，平面非均 质性严重，纵向上发育厚度小，且与高含水层呈交互分布。二次加密后未动用的剩余油， 都是难采的剩余油。如何进行井网加密，改善开发效果，提高薄差油层采收率，是广大 油田开发者面临的紧迫任务。 本文在萨南四—八区地质解剖所取得丰富精细地质研究成果的基础上，结合密闭取 芯井资料、神经网络技术及综合分析方法，对剩余油分布进行了深入研究。通过经济效 益分析，对可采储量、可调厚度指标、最新射孔层段进行了评价。提出了几种不同的加 密调整方式，进行了优劣性对比，确定出了最适合的加密方案。通过南五区西块开展三 次加密调整先导性试验，取得了较好的效果，达到了加密调整方案的设计要求，根据当 时油价，采用“均匀布井、选择性钻井”的布井方式，优先设计首钻井 411 口，取得了 较好的开发效果。后期随着油价上升，根据区块含水率状况，应用综合分析及数值模拟 等方法，落实三次加密缓钻井的可调厚度及钻井经济界限，对缓钻井实施钻井进行评价， 计算缓钻井实施的经济效益，开展了三次加密缓钻井可行性研究，设计了三次加密缓钻 井 416 口，从而完成了对南四-八区的整体三次加密调整。研究成果为其他区块开展加 密调整积累了丰富经验，同时为新一批加密调整布井提供了依据。 关键词，薄差油层 井网加密 剩余油 开发效果 经济评价The feasibility study of well infilling in thin and poor reservoir Abstract As Daqing oil field is of non-homogeneous sandstone， with the extension of oil development and the increasing of water cut， the oil and water distribution becomes more and more complex，and the vertical multi-formation seeing water and high water-cut is common phenomena，at the same time， the potential enhancing oil recovery is more difficult for the scattered remaining oil distribution. In order to improve development performance and make up for the oil production decreasing trends， it has caused much attention about the method of economical and effective well pattern infilling adjustment. Sa-nan 4-8 zone are outer front deposition in three delta area， especially for those thin oil layer and outer stable， as the adjustment Object of three well infilling. Sa-nan 4-8 zone are mainly outside the frontier sedimentary facies， where areal heterogeneity serious， the vertical development of small thickness， and interacting with the distribution of high water-cut layer. In general， the remaining oil is always difficult to recovery after secondary well infilling. Based on this condition， new well infilling adjustment method are necessary for enhancing oil recovery and ensure stable oil production， which becomes a great challenge for petroleum industry. The fine geological description method was firstly applied on Sa-nan 4-8 zone， and a series detailed geological research results has been achieved. Combining with the data of confined core and neural network technology， the residual oil distribution was studied by comprehensive analysis methods. According to economic benefits assessment ， the recoverable reserves， adjustable thickness and the latest interval layers were evaluated. Several different well infilling methods were studied and compared in order to choose a suitable infilling method. Through three field well infilling experiments in south 5 zone west block， the oil recovery achieved good results. According to the oil price at that time，by uniform well designing and partly drilling methods，411 wells were drilled in priority， well development results has been achieved. With the increasing of oil price in later， based on the water-cut conditions in this area， the adjustable thickness are determined and economical boundaries of drilling are studied by comprehensive analysis and numerical simulation. The wells waiting to be drilled were also evaluated by studying its potential economical benefits. the feasibility of third infilling wells has been studied by designing 416 wells for the third infilling wells，By above methods，the whole third wells infilling in Sa-nan 4-8 zone has been adjusted. This study results will prepare experiment for other zones or new well infilling adjustment. Key words，thin and poor reservoir; well infilling; remaining oil；effect of development； economic evaluation创新点摘要 本文首先在区块内进行精细地质解剖，研究油层沉积特征；利用动、静态资料、生 产数据、历年来测试资料，研究油层动用状况，落实油层剩余油厚度及分布特点；进行 经济界限研究，确定可调厚度下限，研究加密调整的可行性，确定布井方式；结合现井 网特点，优选加密调整布井方案。采取动态和静态、多学科结合、系统分析的方法，在 以下几方面取得了一定的突破。 1．一是对三次加密调整的指标进行了综合评价，可根据油价的变化，实施不同的 技术标准，确保实现加密调整总体效益。 2．创新了井网加密方式，突破了常规思路。按照以前的加密方法，多采用均匀加 密方式，本文提出均匀布井，不均匀钻井的加密方式，即保证了加密调整方案的总体部 署，又避免出现低效井，确保了加密调整的经济效益。 3．三次加密调整井位为后期的薄差层三次留有余地。目 录 摘要............................................................................................................................................ II Abstract ......................................................................................................................................... III 前 言.............................................................................................................................................1 第一章 区块地质概况及开发简史.............................................................................................4 1.1 区块地质概况.................................................................................................................... 4 1.1.1 大庆长垣地质特征.................................................................................................. 4 1.1.2 南四—八区地质概况.............................................................................................. 6 1.2 区块开发历程................................................................................................................. 12 第二章 区块剩余油研究...........................................................................................................14 2.1 区块剩余油挖潜能力分析.............................................................................................. 14 2.1.1 表外层为主力未动用砂岩层................................................................................ 14 2.1.2 确定未水洗层以砂岩厚度为主............................................................................ 14 2.1.3 分析未动用砂岩厚度也以表外层为主................................................................ 14 2.2 剩余油宏观分布特征...................................................................................................... 15 2.2.1 剩余油从油层发育状况看以岩性、物性较差的薄层为主................................ 15 2.2.2 剩余油主要分布在外前缘相砂体中.................................................................... 15 2.2.3 剩余油按形成类型来看主要以注采不完善型为主............................................ 15 2.2.4 剩余油在平面上分布不连续................................................................................ 16 2.3 微观上的剩余油分布特征.............................................................................................. 17 第三章 加密调整试验区的效果评价.........................................................................................19 3.1 加密区块剩余油情况...................................................................................................... 19 3.1.1 应用几种不同方法对剩余油进行研究................................................................ 19 3.1.2 区块剩余油类型分类............................................................................................ 19 3.2 对南五区加密效果分析.................................................................................................. 20 3.2.1 产能效果分析........................................................................................................ 20 3.2.2 对薄差油层水驱控制程度较高............................................................................ 21 3.2.3 新的加密调整主要侧重于改善薄差油层的利用............................................... 21 3.2.4 加密调整提高了区块的采收率............................................................................ 22 3.3 试验区效益评价.............................................................................................................. 22 3.3.1 可采储量预测........................................................................................................ 22 3.3.2 经济评价................................................................................................................ 22 3.4 试验区所取得的认识...................................................................................................... 22 第四章 区块加密调整可行性研究...........................................................................................244.1 目前井网密度条件下有一定的调整余地...................................................................... 24 4.2 单井的厚度分析.............................................................................................................. 24 4.3 有效可采储量的评价...................................................................................................... 25 4.4 加密井调整的厚度分析.................................................................................................. 26 4.5 研究三次加密调整思路.................................................................................................. 26 第五章 加密方案设计及效果预测.............................................................................................28 5.1 加密井网部署原则.......................................................................................................... 28 5.2 方案设计和优选.............................................................................................................. 28 5.3 加密效果预测................................................................................................................. 29 第六章 加密井网首钻井开发效果评价.....................................................................................30 6.1 三次加密调整井投产后，区块水驱控制程度得到提高.............................................. 30 6.2 薄差油层动用状况得到改善.......................................................................................... 30 6.3 三次加密调整减缓了水驱自然递减率.......................................................................... 31 6.4 薄差油层注采井距缩小，区块可采储量增加.............................................................. 31 6.5 三次加密加速开采及老井受效分析.............................................................................. 31 第七章 加密井网缓钻井可行性研究.........................................................................................33 7.1 研究南四－杏一区三次加密缓钻井的可调厚度......................................................... 33 7.2 研究三次加密缓钻井经济界限...................................................................................... 35 7.3 优选缓钻井实施方案...................................................................................................... 36 7.4 三次加密缓钻井开发效果预测...................................................................................... 37 7.5 选取南七区－杏一区东部作为三次加密缓钻井首钻区块.......................................... 37 结 论...........................................................................................................................................38