The Study Of Sequence Stratigraphy And Depositional Facies Of Silurian In The Tarim Basin

The study area of this paper is the Tarim Basin, and the target layer is SilurianFormation.The author combines the study of the biostratum, sequence stratigraphy,sedimentary facies and reservoir at home and abroad, directes by the theory ofsequence stratigraphy, which combines well drilling, well logging and the analysis ofseismic, divides the sequence and tract of the single well, and then compares theprofile. After that, the framework of the sequence stratigraphy is built up, and theauthor detailed analyzed the combination of the sedimentary facies and the systemtract. The author researches the plane distributes of the sedimentary facies with thesystem tract as the equitime unit and confirms the major control factor and theevolution of the sequence. On the top of that, directed by the theory of thesedimentation and reservoir geology, the author overall utilizes the core and the thin.And then on the basis of the reservoir physical property and the feature of the poreconfiguration, researches the relationships between Sequenceand the combination ofreservoir, Get the distribution of reservoir sand. Above all the analysis results,combined with hydrocarbon accumulation, predict the favorable reservoir in the studyarea zone.Have a major impact on the Silurian of Tarim basin tectonic movement iscaledonian middle tectonic movement, caledonian adwanced tectonic movement andhercynian early tectonic movement.The caledonian middle tectonic movement formeda nearly North-South of long depression of the Tarim plate.Clastic sedimentary faciesdistribution have an important impact on the caledonian middle tectonic movement.Lower Silurian tidal sediments associated with the stereotypes of the ancientCaledonian medium-term structural movement landform patterns. Silurian sedimentin caledonian adwanced tectonic movement suffered a strong erosion,basin upliftgenerally missing in the Middle-Upper Silurian. The Devonian and Silurian formationwith a parallel between the unconformity, the nearly North-South of long depressionof the Tarim plate Is further aggravated.The hercynian early tectonic movement madethe Tazhong uplift and the Tabei uplift uplifting, deformation, suffered anunprecedented scale erosion.,and in a nearly North-South structural patternsuperimposed on the basis of the structure of the Near East-impact,and played animportant role in controlling. the Tabei uplift Silurian clastic rocks distribution. Comprehensive analysis of previous rock stratum,biostratigraphic and seismicstratigraphy results, according to ancient fossil materials, paleomagnetic data,thedistribution layer and the distribution range of the bituminous sandstone, prove thatthe yimugantawu formation is the Devonian strata and Identifyi that the Silurian,Devonian stratigraphic scheme.Through Petrology, sedimentary structures, paleontology and comprehensiveanalysis of well logs, seismic and other geophysical signs, System Division ofdepositional system of Silurian in Tarim basin. Think of Silurian in Tarim basindepositional systems mainly for coastal-clastic rocks in shallow water. Residues oflower Silurian in keping Tower main barrier of coastal group and the tataaiertageGroup (tidal) clip transgressive phase formation of clastic sediments in shallow water,towers in the Southeast and the Peacock River clastic rocks in the region Piedmontwith fan-Delta deposits.Comprehensive analysis of chronostratigraphic, rock stratum, biostratigraphicand seismic stratigraphy results, combination deposition system and the constructedgeological background analysis, on the basis of dividing the sequence interface andthe internal system tract interface in detail, Using theories and methods of classicalsequence stratigraphy, carried out a detailed study on the single well of sequenceinterface marks and the sequence characteristics, the Silurian in Tarim basin is dividedinto3third order sequence,5system tract. By studying6backbone profiles whichcontrol the work area and more than180auxiliary profile, establish the sequencestratigraphic framework of the silurian in tarim basin, Analysis of main control factorsof development of third order e sequence and established sedimentary model ofSilurian.Integrated sequence and sedimentary, combined with the evaluation of oil andgas shows and previous research, analysis and study of reservoir characteristics, thatthere are3sets of sequence-related reservoir seal assemblage:①composed ofSQ1-TST-HST (Kepingtage group lower segmen) sand ping-mixed ping sandstone(reservoir)--SQ2-TST (Kepingtage group medium segment) shelf mudstone (seal)composition;②composed of SQ2-HST (Kepingtage group upper segment) sandping-mixed ping sandstone (reservoir)--SQ3-TST (Tataaiertage group lower segment)mud ping-mixed ping mudstone,and siltstone (seal) composition;③composed ofSQ3-HST (Tataaiertage group upper segment) sand ping-mixed ping, and Deltasandstone (reservoir)--Yimugantawu Group Ping-mixed group mudstone(seal).