Logging Interpretation Method Of Xing-Ma Buried Hill Reservoir In Liaohe Depression

After decades of exploration and development, Liaohe Oilfield has found a large numberof complex lithologic reservoirs such as carbonate rocks, igneous, metamorphic and so on,and has obtained high-yield industrial oil flow in such complex lithologic reservoirs, andbenefits a lot from it. During the past3years, Liaohe depressed Archean group metamorphicrock buried hill is a very important area to increase proven reserves in Liaohe oilfield.XingLongtai buried hill reservoir produced a million tons capacity has prompt up in2010.Although complex lithologic reservoir logging interpretation method has developed a lot bothin and outside our country, there are still some problems to be settled urgently in Archeangroup metamorphic rock buried hill reservoir logging evaluation. In this paper, we use “corescale logging technology”, comprehensive theoretical method and simulation wellexperimental method to set up the automatic lithology identification method, rock andmineral content calculation, the matrix porosity and secondary porosity calculation methodand fracture identification and fracture parameters calculation method.We use mod logging cuttings, rotary sidewall coring and the slice core identificationresult of XingGu, ChenGu, MaGu buried hill, combined with the logging responsecharacteristics and using the extreme variance cluster analysis method to identify the twodifferent logging curves(Jagged and flat-shaped) of the different lithology. We also use2D,3Dvisualization technology in crossplot method, fuzzy mathematics, neural networks andcomprehensive analysis method to identify the lithology automatically. We have dealt withactual logging data to identify the7lithology(mixed granite class, mixed gneiss, gneisses,amphibolites, granite, diorite and lamprophyre class), and the lithology identification result ofthe25well is90%or more meet with the actual result. Based on the core experimental data,we can accurately calculate the rock mineral content, matrix porosity and oil/gas saturationby using multi-mineral model. Based on the acoustoelectric imaging logging experimentaldata, we use porosity spectrum analysis method to explain the matrix porosity and secondaryporosity, and then combined with the imaging logging, multipole array acoustic logging,cross-dipole sonic log to identify the buried hill crack. Based on the acoustoelectricattenuation theory, combined with simulation well crack imaging logging experiment, derive the crack width calculation formula, and then use test oil, trial mining data andcomprehensive logging data to set up the buried hill reservoir evaluation standard. Combinedwith the trial mining data, mod logging and sidewall coring data, using comprehensivelogging data to evaluate the effectiveness of buried hill reservoir. After comprehensive study,we found that: mixed granite, mixed gneiss and diorite class in XingMa buried hill reservoiris with high porosity and permeability. The lithology intrusive rocks thickness is increasedfrom MaGu to XingGu and then ChenGu buried hills. In north part ChenGu buried hill, it ismainly the neutral acid intrusive rocks, and in the middle part XingGu buried hill, it is mainlygneiss and migmatite, in the south MaGu buried hill, it is mainly migmatite. The groundstress of XingMa buried hill tectonic zone is from North-east to south-west. In XingGuburied hill, the stress concentration area, crack developed, the reservoir net gross is high,there is no obvious correspondence between reservoir develop extent and buried depth. Thereservoir develop extent is becoming worse with the order mixed granite, mixed gneiss andgneiss in the metamorphic class, and the order acid magmatic rocks, neutral magmatic rocksand mafic magmatic rocks in the magmatic rock class. Hornblendite, amphibolite rocks,lamprophyre and diabase dikes are undeveloped reservoirs, they are non-reservoir rocks, andand provide beneficial support in exploration of metamorphic buried hill reservoir.