Font Size: a A A

Sedimentary Facies And Reservoir Characteristics Of Triassic Sandstones In Estern Sangtamu Area, Tarim Basin

Posted on:2015-07-25Degree:MasterType:Thesis
Country:ChinaCandidate:Q M HuFull Text:PDF
GTID:2180330467461364Subject:Sedimentology
Abstract/Summary:PDF Full Text Request
Located in the middle south of Shaya uplift, Akekule salient reaches north toYakela salient,south to Mangar Depression,east to Caohu Depression,andwest to Halahatang depression. It’s a large nose salient, whose main body isPaleozoic and slopes southwestward. Its coverage area is about6000km2.It can bedivided into five secondary tectonic units. The salient experiences four satages offormation, transformation, Inheritance and Development,and structure evolution.Sangdong, the research area of this thesis, is located in the southern slope ofAkekule salient.Base on the achievements of the reserch area’s structure, strata, sedimentary,oil and gas reservoir in Trassic, combining with multiple disciplines including highresolution sequence stratigraphy, sedimentology, reservoir geology, Logginggeology and seismic sedimentology, comprehensively using the drilling, loggingand seismic data, the thesis has studied high resolution sequence stratigraphy,sedimentary system types and characteristics, reservoir characteristics,and reservoirsand development pattern. The research results are obtained as following.By the analysis of core,drilling,log and seismic data,with the previousresearch results,we set up the classification scheme of Trassic high resolutionsequence stratigraphy in Sangdong. The divisional precept of high resolutionsequence stratigraphy has been concluded that the Trassic strata of Sangdong isdivided into two super long-term sedimentary cycles(SLSC1~SLSC2),four long-term sedimentary cycles(TLSC1~TLSC4)and nine middle-term sedimentarycycle(TMSC1~TMSC9).The structure of short term cycles in the research area mainly contains sixtypes, including A1、A2、B、C1、C2and C3. Sandstone in A1and A2is themost developed. The sandstone is mainly developed in TMSC3, TMSC4, TMSC8,TMSC5rising cycle and TMSC6rising cycle. Base on the study of the sandstonedistributing characteristics within the high-resolution sequence framework, we gotthe cause of formation of Triassic sandstone. The Triassic sandstones were mainlyformed by underwater distributary channel, and secondly were sand body formedby deposition of estuary dam and bar.By thin section and SEM analysis, we studied the reservoir petrologycharacteristics, diagenesis, pore types and characteristics, and made clear the reservoir space types in the study area. The types of main sandstone are lithicarkoses. Constructive diagenesis contains compaction,pressure-solution andcementation,Destructive diagenesis contains dissolution and fracturing. The studyarea reservoir space is mainly composed of intergranular pore, and intragranularsolution pores content is not high, whose contribution to the reservoir is little. Thereservoirin T2a1and T2a3is middle prosperous and middle-high permeable,thereservoir in T3h and T2a1contains ultra-low and middle prosperous and middle-highpermeable.Base on the identification marks of sedimentary facies in the research area, werecognize the main Trassic sedimentary system types in Sangdong. The sedimentarysystem types in Trassic contain braided river deltas and lakes. There develops braidedriver delta in TLSC2, TLSC3and TMSC8, and lake in TLSC1and TLSC9.By investigation of the controlling factors of distribution of sandstone body, wethink the development of reservoir sand is affected by sedimentation anddiagenesis,and then predict the favorable areas for reservoir development. Aroundwell TK7202-T902-S31-S28in TMSC6, well TK918-T940-DK41-DK32X in therising cycle of TMSC7, well TK7202-T902-T903and S101-S1071-AT37in thedropping cycle of TMSC7are the avail area for reservoir upgrowth.
Keywords/Search Tags:High Resolution Sequence Stratigraphy, Base Level Cycle, Sedimentary Facies, Reservoir Characteristics, Triassic SangDong
PDF Full Text Request
Related items