【作者】 王岩楼；

【导师】 杨树锋； 沈晓华；

【作者基本信息】 浙江大学 ， 地质学， 2007， 博士

【摘要】 随着大庆西部外围油田开发的不断深入,后备储量动用难度越来越大,以葡西油田为代表的特低渗透复杂油气藏已成为目前油田开发的主要对象。该类油藏虽然储量资源较丰富,但储层薄、物性差、发育不稳定,储层特征难以掌握,钻井风险大;同时储层含泥、含钙、厚度小、流体类型多样、油水关系复杂等因素均掩盖了油水的电性响应特征,油水层解释符合率低。针对以上制约油田开发的瓶颈问题,本论文以葡西油田为研究对象,开展了特低渗透油气藏储层特征与流体识别研究,取得了以下研究成果:1.对葡西油田葡萄花油层开展了以高分辨率层序地层学理论指导的沉积特征研究,将葡萄花油层分成上、中、下三个四级层序8个体系域。另外由于多级次河流改道和河道决口,葡萄花油层保留了许多自旋回作用形成的更次级旋回地质记录,因此将葡西油田葡萄花油层进一步细分为葡Ⅰ1-11个小层,其中葡Ⅰ1-3为上砂岩组,葡Ⅰ4-6为中砂岩组,葡Ⅰ7-11为下砂岩组。2.在上述层序地层学系统研究基础上,综合利用岩心、录井、测井及地震等资料,对葡西油田葡萄花油层沉积体系进行了深入的研究,确定了葡西油田葡萄花油层主要发育三角洲前缘亚相沉积,水下分流河道、分流河道间薄层砂、河口坝、席状砂为主要微相类型;储层砂体分布零星,平面上砂体呈短条带状、串珠状,透镜体状零星分布,纵向上砂体连通性差,砂泥比低,属于典型的“泥包砂”沉积模式。3.在岩心观察、成像测井、动态分析等常规方法研究裂缝的基础上,重点利用无源微地震法对裂缝发育规模与程度进行了有效预测。从监测结果看该油藏中存在一定构造裂缝,且以高角缝为主,裂缝走向以北东东向为主,该方向反映了应力场的作用和影响,接近最大水平主应力方向。其次为北西西向裂缝,反映原生裂隙带的存在。这些裂缝的存在对油层流体识别、注水方案的编制以及油田的后期开发调整存在着较大的影响。4.在总结含不同种类流体储层的测井响应特征的基础上,研究了相应的测井响应机理,认为葡萄花油气藏中的低电阻率油层主要由薄层、薄互层、高束缚水饱和度、高泥质含量引起;高电阻率水层的形成是由于水层中含钙或含残余油,导致电阻率升高。5.针对常规流体识别方法解释符合率低的问题,开展了特低渗透复杂储层的流体识别技术研究。建立了分类图版法,即首先建立粉砂岩、细粉砂岩、含钙致密砂岩、泥质粉砂岩的岩性识别图版,然后根据不同类型储层再建立相应的流体识别图版,此种方法有效地提高了复杂储层流体识别能力。通过本论文的研究,解决了制约葡西油田开发的“瓶颈”问题,为葡西油田的大面积开发提供了技术支撑,同时也为大庆油田长垣以西地区的他拉哈、新肇等低渗透油水同层油藏的动用、开发提供了借鉴。更多还原

【Abstract】 With the development of the exploitation of the western peripheral area of Daqing oil field, it is more and more difficult to use the mothball reserves, so that the exploitation of the low permeability reservoir that representative by Puxi oil field becomes the main exploitation object at present. This kind of oil reservoir keeps more abundant resource, but because of the thin reservoir, bad physical property and unstable development, it is difficult to control the reservoir characteristics and drilling technology, simultaneously, because of the argilliferous, calcareous and thin of the reservoir, multiple types of fluid and complexity of the oil and water relationship, it is difficult to recognize the electric nature of the oil and water and made the low coincidence rate of the interpretation of the oil and water layer. So, in this paper we based on Puxi oil filed developed the fluids identification method and studied the prediction of the potential area of the extra-low permeability reservoir. The contributions of this paper are as follows:1. Developed the deposition nature of the Putaohua oil layer in Puxi oil filed based on the theory of high resolution sequence stratigraphy, separate the Putaohua oli layer into three four-stage sequence(eight systems tracts) Additionally, because of the multiple diversion of river course and crevasse of river channel, there are many secondary cycle geologic record generated by autocyclicity effect, So Putaohua oil layer was separated into eleven layers named PI1-11, where PI1-3is top sandstone group, PI4-6 is middle sandstone group and PI7-11 is underneath sandstone group.2. Based on the above research on sequence stratigraphy, make use of the drill core, mud logging, logging and seismic materials, we do research on the deposit systems of Putaohua oil layer in Puxi oil field, make certain that Putaohua oil layer in Puxi oil field mainly develop delta front intrafacies, main microfacies types are subaqueous distributary channel, lie in distributary channel, mouth bar and sand sheet, because sand body of reservoir distribute discretely, sand body distribute as short strips, moniliformiy and lenses discretely. Sand body connectedness is bad on vertical, heavy clay content. We make certain that this is typically "mud pack sand" deposition type.3. Based on the research of cracks conventional methods such as core observation, image logging, dynamic analysis, we predict the cracks scale effectively mainly by the no-source microseismic. From the result of detection, we can get there are some structure cracks in this reservoir and it is mainly high-angle cracks, the trend is east-north-east. The trend mainly presented the effect and affection of the stress pattern, it is close to the direction of maximum principal stress. Second is north-west- west cracks, it indicates original existence of cracks. The existence of cracks affects the liquid identification of the oil layer, injection strategy and the late development adjustment of the oil field.4. Based on the summary of reservoir logging response that has different kinds of liquid, study on the corresponding logging response mechanism, we think that the low resistance oil layer of Putaohua reservoir was caused by thin layer, high bound water saturation, high shale content, the formation of high resistance water layer is because there is calcium or irreducible oil, so that the resistance become high.5.Develop the study of fluid identification technology of low permeability complex reservoir in view of the problem of the low interpretation coincidence rate. Build up the classification chart method, it is first build up the lithology identification chart of the siltstone, lepto siltstone, calcium tight sandstone, argillaceous siltstone, then according to the different kinds of reservoir, build up the corresponding fluid identification chart, this method improve the identification ability of complex reservoir effectively.We resolved the bottleneck problem restricting Puxi oil-field’s development, provided the technique for the big area development of Puxi oil-field via the research in this paper. At the same time, providing reference for the exploitation of the low permeability oil-water layer reservoir like Talaha, Xinzhao , which are in the west in Changyuan of Daqing oil-field.更多还原