Research On Oil/Water Distribution Of Ordovician Reservoir In Langa Fault Zone Of TAHE Oil Field

Langa fault zone is located in the southern slopes band of Uplift zone of Akekulein Tarim basin. The study area experienced regional uplift and erosion, and is generallack of Silurian-Devonian. It formated of a series of folds,fracture and unconformity,strong karstification, and the strong development of the corroded fissure cave.Based on the previous study of tectonic setting and evolution of the entireAkekule, this paper focuses on the analysis of the the Langa FAULTS Characteristicsand evolution of times, distinguishing the fault zone to major faults times, summarizefault layers, strike, dip and nature elements of the main faults in the Langa fault zone.The study summarized the data of drilling blowdown, leakage and rock sliceobservation in the study areaand classfying Ordovician reservoir and percolation spaceinto caves, dissolved holes, cracks and dissolved pores. And in accordance with the fourtypes of storage the infiltration space and conventional logging, the imaging logging（FMI）, test data, test mining, production logging to log interpretation, while makingreference to the structural location of the wells, production dynamics single-wellreservoir description and classification of such information, to take this idea cracks-dissolution porosity, cracks-holes, karst caves type, fracturedreservoir of Tahe Oilfieldthe the Langa fault zone Ordovician divided type: reservoir, and the establishment ofdifferent types of reservoir framing pattern of the study area.The study further the major reservoir types developed in this fault zone forstatistical analysis, compared developmental differences to the various types ofreservoirs in the study area, and get the plane and longitudinal distributioncharacteristics of the various types of reservoirs in the study area.Karst and fracture is the most important factor in this region, hence,with the karstand fault development context, the paper focused on the the Langa fault zoneOrdovician reservoir Karstification mode and controling effects to the reservoirdevelopment of the fractures of the study area. Region Ordovician karst role ofmulti-stage, multi-type development characteristics, including: syngenetic atmosphericwater dissolution, karstification of the middle Caledonian late Caledonian-EarlyHercynian Karstification, late Hercynian hydrothermal dissolution effect. Langafracture reservoir development layer is controlled by faults and karst developmentstrength and space-time configuration. That throw, extending long, strong inheritanceactive fault zone match karst water erosion area, the reservoir is developed. Thesecondary fault zone and with the space and time does not match the strong dissolutionlimited the size of the reservoir development.Make the fluid nature of planar maps, based on the actual drilling test oils and fluids laboratory data, mainly from the ground density of crude oil, crude oil waxcontent, sulfur content of crude oil, formation water salinity, chloride ion concentration,water density, combined with karst ancient topography, fracture, structure analysis ofthe study area the nature of the distribution of the oil, water and variation.Within the logging, oil testing conclusions and production cross-sectional test,production situation analysis of the fault zone, the study developed the theidentification of oil and water layers discrimination, and from which drawning the oiland water layers of each well in the fault zone. After statistical analysis, the papersummed up the distribution of oil and water in the longitudinal and plane direction.Overall, in the longitudinal direction the height of Oil column is short, water column isSpreaded, mainly crude oil rich layer segment to T₇⁴surface is less than60m, the watertoT₇⁴surface is less than100m. No uniform oil-water interface to the hole region, eachFracture-cave brought big differences in the depth of water. Plane, the performance ofthe distribution of the fluid within the fault zone is a strong heterogeneity, the overall oil,but not high abundance of oil and gas along the main fault local enrichment. Oil and gasin the south-rich than the northern, routine testing pressurized water or acid layer wellsare mainly distributed in the vicinity of the main fault S115-3well area, the well areafor the two deep fault intersection region.Withthe basis of the distribution of water and oil, the study analyzedthe controllingfactors on water distribution, and rekoned thatit is mainly affected by the fracture andoil injection. The orientation of water oil injection in this area is from east to west, fromthe southeast to the northwest, which is similar to the fractures. Thehydrocarbonespecially accumulated in the vicinity of the deep fault hydrocarbon.Fracture in the study area made the oil source and the reservoir connected spatially andtemporally,which therefore became the important migration pathways of oil and gas.openingfracture made the oil and gas of northern part of the fault zone oven, making thefault zone north of crude oil is not enriched, while the atmospheric water Penetratedalong the fault with the help of gravity, to some extent hindered the filling of oil and gasthat migrated from south to north, resulting in partial destruction of oil reservoirs of thenorthern edge of the study area, and where the water is active.