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Research On Development Geology Characteristics Of Ordovician Carbonate Reservoir In The Block12of Tahe Oilfield

Posted on:2013-04-03Degree:MasterType:Thesis
Country:ChinaCandidate:Y L WangFull Text:PDF
GTID:2230330377950134Subject:Oil and gas field development geology
Abstract/Summary:PDF Full Text Request
The Ordovician carbonate reservoir in the Block12of Tahe Oilfield belongs tosupper-deep karst aperture-cave reservoir. This reservoir is of great burying depthwhich through many phases structure bursts and the ancient karstifications. Reservoirwith strong heterogeneity of the vertical and lateral, predicted effectively is verydifficult. This reservoir belongs to the ultra-heavy oil reservoir, which is filled withheavy crude with high viscosity. The oil/water relationship of reservoir is extremelycomplication, and it is very difficult to develop this kind of reservoir.Based on summarizing and absorbing the results of previous studies ondevelopment geology character of Ordovician reservoir in Tahe Oilfield, this paper forthe research status about exploration and development in the Block12of TaheOilfield, make full use of geological, seismic, logging, testing and development ofdynamic data, using point-line-surface method to start from the comprehensiveidentification of reservoir types of drilling profiles, to in-depth study the spatialdistribution characteristics of different types fracture-cavity reservoirs and the maincontrolling factors of fractured-cavernous reservoir development and distribution onthe vertical and lateral, and in accordance with the original oil/water distribution andthe dynamic characteristics of development water breakthrough of the single well toin-depth analysis the oil/water distribution characteristic in the Block12, and finallyaccording to the study results on the law of different types fracture-cavity reservoirsdistribution and oil/water distribution to dissect four typical fracture-cavity unit in thestudy area, and advance the corresponding geologic reservoir model. The mainrecognition as follows:(1) On the plane, fractured-cavernous reservoir development with the "Easterncontiguous, middle western zonal " zone distribution characteristics of the Block12inTahe Oilfield, the area of tectonic highlands and fault development area with high rateof drilling, and the degree of development for this reservoir in the Upper Ordovicianerosion area was significantly higher than Upper Ordovician coverage area.Fractured-vuggy reservoir is of poor continuity on the plane, sporadically distributedin the North West and irregular dendritic distributed in the rest, which are mainlydistributed near the main faults and in the Upper Ordovician coverage area which islocated in the south of Sangtamu group wedge out. Fractured reservoir has differentlevels of development in the Block12, and the continuity of this reservoir isgood on the plane, irregular flaky distributed, the degree of development for thefractured reservoir is relatively high and reservoir thickness is relatively large in this area which is on the south of the line TH12410-AD18-TH12347-TH12322-TH12351-TH12325-TH12336.(2) Drilling revealed that fractured-cavernous reservoir can be divided into threesections on the vertical. This reservoir in the first section which below the T74surface0-80m range with the highest degree development, in the second section whichdistance the T74surface80-140m range is poor development, in the third sectionwhich distance the T74surface140-210m range is relatively well development.Similarly, fractured-vuggy reservoir also can be divided into three sections on thevertical. This reservoir in the first section which below the T74surface0-50m rangewith the highest degree development, in the second section which distance the T74surface50-80m range is relatively well development, in the third section whichdistance the T74surface80m below is poor development.(3) The degree of development of ancient karst, fault and its associated fractures,and ancient karst erosion surface to the development of fractured-cavernous reservoirhave an important role in the control effect.(4) On the whole, the Block12of Tahe Oilfield is mainly to store oil, and thewater body just local development, which is of poor contiguous nature. The easternS94CH well block and TH12103well block, the central TH12330well block, TheMidwest AD4well block, AD7well block, TH12403well block and AD6CH wellblock has a high degree of oil and gas accumulation, but the western AD21well block,the central TH12209well block and the eastern AD8-S104CH well block,TH12136-S85well block, in which the water body is of contiguous distribution. Onthe vertical, crude oil is easy filling below the T74surface0-80m range, and thechance of water body development is high distance the T74surface80m below.(5)Fracture-cavity unit generally oil/water coexistence, but rarely present auniform oil/water interface, between each well in the fracture-cavity unit may nothave the flow and pressure connectivity on development. The reservoir of theborehole section can’t be fully representative of the reservoir characteristics of theunderground reservoir unit, the reservoir of the Block12in Tahe is the main of singlewell-controlled cave, the interwell may rely on fractures communication, butconnectivity is poor integral.
Keywords/Search Tags:Tahe Oilfield, Fracture-cavity reservoirs, Spatial distribution, Oil/water distribution, Geologic reservoir model
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