Research On Reservoir Characteristic Of Lower Member Of The Tenggeer Formation In Daerqi Area Of Baiyinchagan Depression

Baiyinchagan Depression,a secondary tectonic unit,belongs to the chuanjing depression of Erlian basin's western margin tectonically.Daerqi area located in the southern depression and the centre of slope zone.Based on the previous studies,comprehensively using the core data,logging data,analysis assay data,this paper studies on the sedimentary faces,petrologic characteristics,pore types and structure,predicts the favorable target area of the study area and provides a basis for rolling exploration deployment.By using the method of rock stratigraphic contrast,taking standard well for Stratigraphic division and correlation in the research area.According to the identified typical sign layer,the grading comparison under the control of the sign layer,skeleton section and sedimentary cycle is adopted.This paper devide the lower segmet formation of Tenggeer's study area into 6 sand groups,which in turn from top to bottom are tx1,tx2,tx3,tx4,tx5,tx6 by the method of marker layer.Based on the results of previous studies and based on the data of core observation and laboratory analysis,has been adopted to find that there are three sedimentary faces in the research area Tengge'er group,the sedimentary of western Daerqi fine grained Braided river delta,as for eastern Daerqi Fan delta and Alluvial fan.Analysising ordinary thin sections and casting thin sections,the study finds out that the sand stone of the research area are mainly lithic sandstone,lithic feldspar sandstone and feldspathic lithic sandstone with a few cuttings arkose,the mineral maturity is low.Western Daerqi's rock structure maturity is high,while eastern Daerqi's is low.The pore type are mainly primary residual hole and secondary opening.The primary intergranular pore in the west area of Dahl is higher than that in the East,indicating that the diagenesis of the west region is weaker than that in the eastern region.The peak of laryngeal width in Dahl's west region is mostly concentrated on 5~7.5 um,and the laryngeal tract is fine.The peak width of the East region is concentrated in 15.5~20 um,and the throat is medium.Diagenesis is in the period A.Mechanical compaction and cementation are the main diagenesis evolution types.Based on the petrological characteristics,Cheng Yan effect and pore structure characteristics of reservoir,combined with the sedimentary types of the study area,the reservoir in the target area of the study area can be divided into three categories.The lower part of tengxia is mainly the type III reservoir of non effective reservoir.