【作者】 王国鹏；

【导师】 郑浚茂；

【作者基本信息】 中国地质大学（北京） ， 矿产普查与勘探， 2006， 博士

【摘要】 安棚油田位于河南省泌阳凹陷的中南部,储层胶结致密,属于特低孔隙度和特低渗透率储层。论文研究了安棚油田特低孔特低渗储层特征,提出了相应的开发技术。安棚油田油藏埋深 2800～3100m,储层属扇三角洲相沉积,发育 5 种微相类型。储层岩性主要为粗-细砂岩和含砾砂岩,储层孔隙度 5-6%,渗透率 1-2×10-3μm2,主要流动孔隙半径较小,分布在 0.47～1.06μm 之间,储层快速堆积,颗粒大小混杂,分选差,成份成熟度和结构成熟度低,是导致砂岩低渗的关键条件。论文对储层中的 2 裂缝进行了深入研究。储层中天然裂缝较发育,采用先进的定向取心和成像测井等天然裂缝识别技术定量确定裂缝组系产状,裂缝走向玫瑰花图反映裂缝的走向为 90～110°,裂缝以高角度或垂直裂缝为主,裂缝间距以 2～3cm 为主,裂缝性质为张性破裂和剪切破裂缝,裂缝成因类型是与区域拉张应力有关的区域性裂缝;地层中裂缝长度分布于 4～30cm 之间,裂缝宽度绝大多数在 1000μm 以下,裂缝平均密度为 0.7 条/m,裂缝孔隙度为 0.2-0.3%。文章分析了安棚油田储层中裂缝的破裂期次。通过对裂缝充填物-次生方解石进行稳定同位素测定,对储层岩石进行声发射实验,确定了储层岩石的破裂期次,研究得到安棚油田储层的天然破裂期次有四期,第二期是主要的破裂期。分析了影响裂缝发育程度的两个方面因素:一为区域构造应力场强度,二为储层岩石的力学性质及厚度,并建立了用于裂缝预测的储层厚度与裂缝间距的相关关系。通过安棚油田储层沉积体系分析表明,安棚鼻状构造的雏形是由地层沉降幅度的差异及扇三角洲相砂泥岩差异压实共同作用形成的, 鼻状构造的形成对裂缝具有积极的改造作用。编绘出了各油组的主应力和主曲率分布图,对各油组的裂缝分布进行了综合预测和评价。安棚油田油气藏类型复杂,有普通黑油油藏、挥发油藏和凝析气藏等。安棚油田为特低渗透油田,油井自然产能低,为了确定有效储层的分布,论文提出综合应用 Hobson 法、产能法、浮力法等得到包含不同流体储层的下限标准,确定了油层和凝析气层有效压裂的物性下限值,为压裂层位的选取和特低渗油气田的有效开发提供了科学依据。最后,针对泌阳凹陷安棚油气藏特低孔特低渗、单井自然产能低(1.5t/d)的特点,以裂缝识别及裂缝分布研究为基础,地应力场特征分析表明人工裂缝方向与最大主应力方向一致,为了提高水驱采收率,提出了相应的开发技术对策,优选裂缝性特低渗油藏的注采井网,低渗透油田由于渗流阻力大,要求井距较小,采油井和注水井连线与裂缝走向呈45°方向部井,延缓方向性水窜及水淹时间。论文还提出开发安棚油田的主要改造措施,包括进行水力压裂、高压增注等,以改善注水开发效果。通过压裂,安棚油田单井日产油从 1.5t 提高到 14.2t,因此,压裂是保证特低渗油田的有效开发的主要措施。更多还原

【Abstract】 There developed tight formations and low-porosity and low-permeability reservoirs inAnpeng Oilfield, Biyang Depression, southwestern of Henan Province, China. This paperdescribed the features of ultra-lowpermeability reservoir and development technologies ofultra-lowpermeability reservoir. The buried depth of reservoir is 2800-3100m. The reservoirs arecomposed of fan-delta sedimentary system. The micro-facies can be subdivided into six types.The composition and texture maturity of reservoir rocks is lower. The principle type of reservoiris sand and sand-conglomerate. The reservoir porosity distribution range 5-6%, the permeabilitydistribution range 1-2×10-3μm2, the mean radius distribution range of reservoir is 0.47-1.06μm.Rapid accumulation, sophistication of different grain sizes, low maturation of texture andcomponent are the key factors that cause low permeability.The paper described the reservoir fracture characteristics. The natural fractures were welldeveloped in the reservoir. Adopt advanced technique such as oriented coring to get the fracturesorientation. The rosette azimuth diagram indicated the fractures orientation range from E90toSE110. Lots of fractures are in the form of high degree or vertical type. The general spacebetween fractures is 2-3 cm. It belongs to the extension and shear fractures. The regional tensilestress is the causes of fracture. The fracture identification technologies such as the oriented coretechnique and acoustic-electric imaging log were used to get the occurrence and distribution offractures. The fractures length distribution range 4-30cm, the fracture apertures are smaller than1000μm, the fracture density is 0.7 per meter, the formation fracture porosity range 0.2-0.3%.The reservoir fracture development periods are analyzed in Anpeng Oilfield, BiyangDepression. There are some secondary calcite fillings in the fractures. The determine ofsecondary calcite stable isotope which fillings in fracture and the acoustic emission tests of thereservoir rocks indicate that there are four fracture generations. The second generation is themain fracture period. There are two main factors to affect the fracture developing, one is thestructure stress field, another is the nature and the thickness of the reservoirs. For fractureprediction we establish the relationship between thickness and fracture space.The analysis on reservoir depositional system indicates the genesis mechanism of Anpengstructural nose and its connection with the generation of reservoir fractures. Point out theco-effect of differential compaction and differential depression are the genesis of Anpengstructural nose. Give the distribution of major principle stress and major principle curvature ofoil measure. Point out the synthesis evaluation of fractures distribution of oil measure in AnpengOilfield .The liquids properties of reservoirs in Anpeng Oilfield are complicated. There are black-oilreservoir,volatileoilandcondensategasreservoir.Thereservoirfeaturesareultra-lowpermeability and low natural well production. Through reservoir evaluation, the papersuggests three methods to acquire cut-off value of ultra -low permeability clastic reservoirswhich bearing various fluids. Those are Hobson method, production ability method andbuoyancy method. In the end, this paper proposed the cut-off value for the effective developmentof extremely -low permeability oil and gas field.Finally, aimed at the reservoir feature of ultra-lowpermeability and low natural wellrate(1.5t per day), basis on reservoir fracture identification and distribution study, the formationstress field analysis indicate the direction of artificial fractures are accord to the direction ofmajor principle stress. In order to enhance the oil recovery of water-flooding, through reservoirfracture identification and distribution study, the paper suggests corresponding developmenttechnologies, optimal flooding patterns in fractured low-permeability sandstone reservoir.Because of the generally low pressure transfer-rate, the producer-injector spacing should berelatively close. Flooding pattern is with the well array direction at 45b with the fracture Strike.An optimized flooding pattern in fractured low-permeability reservoir should delay directionalwater break-through, prolong water flooded time. This paper suggests to adopt stimulationtreatment such as hydraulic fracturing, high pressure injection etc. to improve production rate.Through the hydraulic fracturing, the well production increase from 1.5t to 14.2t per day, thosemeasures are ensured for the development of ultra-lowpermeability oilfield effectively andenhancement the economic benefit.更多还原