海拉尔盆地浅变质岩潜山岩性控储特征及储层岩性序列识别

岩性识别是变质基岩储层评价的核心与难点，以海拉尔盆地贝尔凹陷布达特群浅变质基岩潜山为例，应用岩心、薄片、测井、地震资料，通过测井交会和地震相等方法，识别与建立主要岩性的测井-地震响应标准。从风化淋滤和断裂对储层的改造程度上，分析岩性对构造裂缝、溶蚀孔隙等主要储集空间发育的控制作用。通过岩性、物性、油产量的定量统计方法，建立不同级别储层与岩性序列的对应关系，应用地震频谱聚类、多属性神经网络聚类等物探技术对储层岩性序列进行平面预测。结果表明：布达特群复杂浅变质基岩发育5类9种主要岩性，它们具备不同的测井响应值与地震反射特征。不同岩性的矿物成分、含量、岩石强度、抗风化能力差异性控制储层发育程度及类型。储层岩性序列分为4类，Ⅰ类岩性序列为含火山碎屑沉积岩、正常沉积岩的中-细粒岩，为好储层，日产油大于15 t； Ⅱ类岩性序列为火山碎屑岩，为较好储层，日产油1～15 t； Ⅲ类岩性序列为沉积火山碎屑岩和正常沉积岩中的泥质岩，为中等储层，日产油小于1 t； Ⅳ类岩性序列为中基性火成岩类，为差储层，试油为干层。研究区优质储层发育区主要分布于贝15、贝38、贝32井区和塔拉汗构造带东部与中部地区。

Controlling of epimetamorphic rock lithology on basement reservoir and identification of lithological sequence of reservoir in Hailar Basin

Lithology identification is the key and base work to study metamorphic rock basement reservoirs. Taking the complex epimetamorphic rock basement of Budate Group buried hill in Beir Sag,Hailar basin as an example, the core,thin slice,well log and seismic data were used to establish the log-seismic response standards of the main lithologies through the method of well log crossplot and seismic facies analysis. The controlling effects of lithology on reservoir spaces such as structural fractures and dissolved pores were illuminated,from the aspects of different reform degree by weathering-leaching and faulting effects. According to quantitative statistics of lithologies,reservoir physical properties and oil production,the hierarchical-related correspondence of reservoir and lithological sequence was built. The geophysical methods of seismic spectrum clustering and multi-attribute neural network clustering were applied to predict the distribution of lithological sequence of reservoir. The results show that there are five main types and nine fundamental lithological rocks developed in Budate Group, which have specific well log response values and seismic reflection characteristics. The differences in mineral composition and content,weathering resistance,and rock strength for each lithology control the difference of reservoir type and quality. The lithological sequences of reservoir compose of four levels. The levelⅠis pyroclastic sedimentary rocks and normal medium-fine sedimentary rocks, which is good reservoir, with oil production more than 15 t/d,the level Ⅱ is pyroclastic rocks,which is fair reservoir,with oil production of 1-15 t/d,the level Ⅲ is sedimentary pyroclastic rocks and normal mudstone,which is medium reservoir,with oil production less than 1 t/d, and the level Ⅳ is intermediate-basic volcanic rocks, which is poor reservoir, being dry layer. The high quality reservoirs in the study area are mainly developed in the well fields of Bei 15,Bei 38 and Bei 32,and the eastern and central Talaham structural zone.