Research On Sedimentary Microfacies And Reservoir Characteristics Of Carboniferous Gas Reservoir, In Shaguanping Area, Eastern Sichuan Basin

Regional sedimentary framework,petrology,electrofacies and,microtopography of depositional stage are used to research of mutil-factor sedimentary microfacies in this thesis,as a guidance with sedimentology and geology;As a guidance with carbonate reservoir analysis and evaluation of technology, in order to explore suitable statistical rule, and provide the correct gas reservoir study of the geological model; With the study of the diagenesis, probe into geological characteristics of the reservoir; and take the dynamic evolution of reservoir as the master line, in an attempt to clarify the time-space distribution of reservoir permeability, quality change, and then renders conceptual model of reservoir prediction; Comprehensive calculation the static and dynamic characteristics of Carboniferous gas reservoir,classified and depicted the characterization of the Carboniferous reservoir and permeability units in detail, and then analysised the master control factors of reservoir, predicted favorable areas for exploration and evaluation finally.This thesis acquires the following main outcomes are as follows:The thesis integrated earthquake processing and the explanation achievement first, detailed studies Shaguanping structure ,and depicted its characteristics of faults,structure and traps,added on stratigraphic is opachs of ten meter,mended and composeed structure map of gas field and stratigraphic wedge out of Carboniferous, pieces together structure map of northern structure(Guan 14 well region), and firstly ascertains and demonstrates that altitude of Carboniferous reservoir is within -5100 meter in the Shaguanping structure(altitude of the initial closed line is -4750) expanded the gas range;By observing 5 wells'core and more than 120 thin slices under electron microscope of Carboniferous Huanglong Group in the Shaguanping area, combining Petrology, Paleontology and logging etc. sedimentary facies symbol, and quoting"carbonate sedimentary model of surface of the lake fluctuate in the salted lagoon"to divide the single well depositional microfacies and drew Huanglong group each section's depositional microfacies plane distribution maps, Shallow beach and exposed shallow beach are a beneficial sedimentary facies belt in the lagoon in the central south of Shaguanping;The preferable reservoir of Carboniferous Huanglong Group all growed in the dolomitization dolomite, Diagenetic stages of in the Carboniferous Huanglong Group are divided into syngenesis stage,eogenetic stage I period,epidiagenetic stage,eogenetic stage II period and metaharmosis stage I and II period by researches of thin section analysis,diagenetic evolution series and diagenetic environment。Combining with analysis of sedimentary and diagenetic environment for affecting and reconstructing pore space,diagenetic facies in the second member of Huanglong Group are divided into five types。Porosity types of Carboniferous reservoir pore space are manifold in Shaguanping area,main of which are intergranular pore and dissolution pore types,type of fracture is structural fracture , and gas reservoir's type is fracture porosity reservoir; The carboniferous reservoir has obvious dual medium characters, mainly growingⅡandⅢkinds, but lessⅠkind, The principal producing formation is the second of Huanglong group, mainly sedimentary microfacies are exposing shoal, lagoon beach, and lagoon, these explained that producing gas layer section , deposited micro and physical property mutually matched.By fine descriping and statisticing crack growth character, the research thought that different wells'fracture growth degree of Shaguanping gas field is largely various. The main type of fracture is structural, on longitudinal mainly concentrates in the C2hl2 section, for small horizontal fracture; on crosswise grows in the anticlinal axial region, nearby the big fracture as well as the minor fracture, The core limestone cave grows better, the predominant type for the small backfill hole, the main growth in the nearness axial region nearby Guan 7 well, nearness the big fracture nearby Guan 2 well, the Guan 8 well areas.According to various wells'porosity, permeability parameter, the research divided the Carboniferous reservoir, the 18 well carboniferousⅠ,Ⅱ,Ⅲreservoir near 170 sections of Shaguanping, and on the basis drew up the Carboniferous reservoir well tie contrast and the aerosphere distribution sectional drawings of Carboniferous reservoir, thought the continuity of reservoir on the crosswise was good. The natural gas still occupied the structure high spot, infiltration reservoir area medium high abundance distribution high.Synthetically utilizing deformational trap shape, various gas wells effective reservoir total thickness,Ⅰ+Ⅱreservoir thickness and proportion, the gas well open flow capacity, the well test penetration coefficient, the dynamic reserves size, the gas well deliverability, the earthquake predicted achievement of reservoir, the sedimentary facies and the fracture spacing character and so on, the research divided reservoir and infiltration units of gas field in Shaguanping area, and drew up plane distribution map of the gas pool middle~high infiltration area, low infiltration area; Moreover, through (Guan 010-X1 well) analyzing the achievement of new well drilling in Shaguanping, it found that using highly deviated well to propose the high production in this structures was completely feasible and the effect was extremely obvious.Through analyzing hydrocarbon pooling conditions of Carboniferous Huanglong group in, Comprehensive utilized the theories on dynamics of hydrocarbon accumulation, the reserach thought this structure had forming the big natural gas field's precondition. Comprehensive Considered control reservoir growth primary factors, it divided into 4 sub-areas for predicting and evaluating and appraising of Shaguanping structure, main body of the structure is the most advantageous explored goal, although out of the main body elevation -4400m periphery region appraise the more advantageous region, its gas bearing area and reservoir thickness were both preferable, and also the exploration mining degree was low, listed as the next natural gas exploration key point of carboniferous Huanglong group in Shaguanping.