The Characteristics And Reservoir Forming Pattern Of Houba Jurassic Oil Sands In Sichuan Basin

In recent years, the oil prices continued growth in world.Along with thecontinuous development of science and technology,oil sands as conventional oil andgas major alternative energy, begin to become the object of people's attention.The oilsands resource are abundant in China, but the oil sands industry developed lately is stillin the survey and preliminary research stage. In recent years, oil companies, researchinstitutions, private enterprises and other institutions in China, work on the oil sandsinvestigation, exploration and exploitation , and make the exploration and developmentof oil sands in China has great progress. The Houba oil sands is the thesis of the secondbatch of national oil and gas resources survey and evaluation of strategic areas ,which iscalled: The evaluation and optimization of the potential target about oil sands depositsin northern China.This article study the ore-controlling structure and deposition characteristics ofHouba oil sands by surveying the structure profiles, oil sands outcrops and shallowdrilled well in the field; study the hydrocarbon source rocks of the lower of Shaximiaoformation by collecting data and chemical test and analysis of oil sands in study area;study the conditions of reservoir and seal by observing the microscope of oil sands inoutcrop and core with the chemical test and analysis results. At the end we can establishthe reservoir forming pattern of Houba Jurassic oil sands by combinig with oil and gasgeological characteristics, geochemical characteristics of oil sands samples and thestudy of tectonic movement.After field surveys ,we found that the Houba oil sands are exposed to highwaysbetween Town Houba and Qinglin kou along the roads and rivers, lower Shaximiaostrata expose over the whole formation to 45±10°, dip 40-50°, South-South Easttilt.Main lithologies are gray - dark gray feldspathic lithic sandstone, in which themedium-coarse sandstone have the best oiliness, as full of oil. So lower Shaximiaostrata are good reservoir properties.The project's study found that oil sands of Shaximiao formed in the delta and lakeenvironment.This study can identify three-sub-phase (shallow lacustrine, delta plainand delta front) and ten-micro-phase (static cement, turbidity current, subaqueous fan,distributary channel, natural levee, interchannel, underwater distributary channel,mouth bar, distal bar, and inter bay ) by the analysis of core drilled through the wild,mineral microscopy indoor and particle size.Oil sands oil have suffered serious biological degradation. The study area is located in western Sichuan Foreland Basin, it is the outer edge ofLongmen Shan thrust fault with a monoclinic structure ,Longmen Shan thrust beltwhich is the typical foreland thrust belt has a complex tectonic deformationstyle.Previous studies show that Longmenshan thrust belt in the material composition,deformation level, intensity of deformation and tectonic style has some obviouszonations. Longmen Shan thrust belt is divided into pre-mountain zone three tectonicsub-zone and two regional oil sand ore belt that Tang Wang Village– Yang Tian WoKlippe - gliding tectonic sub-zone, Lou Zi Bar– Yan Men Bar– Ma Jiao Bar imbricatethrust subzones, Kuang Shan Liang– Tian Jing Shan - Er Lang Miao thrust anticlinesub-zone and Kuang Shan Liang– Tian Jing Shan– Er Lang Miao and Jin Zi Shan -Qing Lin Kou–Houba metallogenic belt of oil sands.The advantages of reservoir foming of Houba oil sands in Sichuan Basin are that:①According to stable carbon isotope testing and biomarker compounds of contrast,Jurassic oil sands oil come from Cambrian source rocks, a rich oil source ; goo②dreservoir properties to provide a favorable storage space for hydrocarbon accumulation;③the controlling role of structure to the oil sands accumulation. Which theconstruction of numerous styles and multiple views in the area plays a vital role in oiland gas the formation: a,Longmen Shan section tectonic zone control the oil sands information and distribution of mineralization belt; b,different structural types controlthe oil sands in reservoir forming pattern.Thrust faults, joint developpped zone andhigh porosity medium-coarse sandstone formation in good configuration are majorcontrolling factors of oil sandstone,another of Himalayan tectonic tilting, faulttransportation and piedmont erosion are necessary conditions for the formation andpreservation of oil sandstone.Such a large reservoir of oil sands resources is a natural laboratory, theestablishment of the oil sands reservoir forming pattern can not only control the area ofpetroleum geological conditions but also be favorable for China's exploration anddevelopment of oil sands resources and provide a favorable basis.