Font Size: a A A

Study On Reservoir Characteristics Of Tenger Formation Of Xilinhaolai Area In Baiyinchagan Depression

Posted on:2014-05-21Degree:MasterType:Thesis
Country:ChinaCandidate:Z C LeiFull Text:PDF
GTID:2250330401480764Subject:Mineral prospecting and exploration
Abstract/Summary:PDF Full Text Request
Baiyinchagan depression is located at the west edge of Erlian basin, which is a second structure of Chuanjing sag. It’s west and north is adjacent to Baolige uplift, in the south is Saihuduge svmon fault,the NEE to distribution.Xilinhaolai is located at the south ramp region of Baiyinchagan depression, with area of160Km2and78wells. The target strata of the research area is Tenger Formation in Lower Cretaceous. With the further exploration and development, many complex geological conditions are gradually expose, such as plenty of oil-bearing fault blocks, oil-bearing series and ambiguous exhibitioin of sand body. Aiming at the existing problem of the study area, based on the theory of Sedimentology and Petroleum geology as this article guideline. Depending on the theory of high resolution sequence stratigraphy and sedimentary system analysis to establish isochronous stratigraphy frame of study area exploration strata, fine describe reservoir sand body of microfacies, development pattern and spatial distribution regular pattern, combine with seismic, well drilling, well core sample’s analysis, test and some relative data, conferring former study achievements of other researchers, Tenger formation microfacies, the characteristics of reservoir petrology, the characteristics of microscopic pore structure, diagenesis, reservoir heterogeneity and influencing factors of the reservoir. And then point out the favorable exploration target, which is instructive and meaningful to the further exploration.Based on the well core observation and integrated logging data interpretation divide and correlate substrata, establish substrata system under the control of high-resolution sequence. Use rock stratigraphy and high-resolution sequence stratigraphy as guide, apply point-line-surface trinity method,78wells are fine divided and correlated, and fine model of single layers is also established.Through the core data, log analysis, particle size analysis and regional geological background, we determine that the research area is a braided river delta deposit. Mainly development delta front subfacies and the former delta subfacies. The delta front subfacies include underwater distributary channel, river mouth bar, distal bar, sand sheet and so on, development a set of dolomitic mudstone reservoir sedimentary bodies in the center of sag. The sediment source mainly comes from the south and southwest of ancient bump.The result of oilness statistics to each kind of reservoir rock indicate that fine sandstone is the main oil reservoir, dolomitic mudstone distribution in the study area is very less on all horizon distribution area is relatively small, accounts for6.9%of the total reservoir, it’s thickness of logging in oil&gas shows account for16.2%of the total reservoir, well logging interpretation oil content account for8.88%of the all reservoir thickness, sandstone thickness accounted for92.8%of the total reservoir, while the logging in oil&gas accounts for83.4%of all reservoir shows according to thickness, thickness of log interpretation oil accounted for90.8%of all reservoirs show that dolomitic mudstone reservoir oilness rate higher than that of sandstone reservoir. The key oil layer in the study area are txl, ts3and ts2sand group and dolomite mudstone reservoir mainly distribute in the tx1, ts3and ts2sand group.Based on the modern analytical techniques such as the microscope, electron microscope scanning and thin Member identification and so on, we analyze the reservoir petrologic characteristics and diagenesis deeply. The study suggests that the reservoir sandstone’s compositional maturity of Tenger Formation is medium low. Litharenite is the main reservoir sandstone, as well as development little lithic quartz sandstone and feldspar lithic quartz sandstone. The Tenger Formation is in the lately diagenesis A stage, has experienced s series of diagenesis such as compaction, cementation and authigenic mineral deposition, metasomatism, corrosion, dissolution and so on, which the compaction and the cementation make the reservoir properties bad, but the dissolution developed widely in the area improve the physical properties to some extent. We found a new reservoir stratum through reservoir petrology analysis, which is dolomitic mudstone.Reservoir pore type features with a mixture of primary pore and secondary pore are both development, pore types are mainly intergranular pore, mould pore and fracture porosity,etc. of which the most intergranular pore development; Throat types are mainly porosity narrow throat, contraction, flake throat and microthroat; Pore structure is characterized by fine pore throat to small throat with small pore, low coordination number. Different microfacies of underwater distributary channel and sand sheet with better pore structure, river mouth bars, turbidite body with poor pore structure.The reservoir of dolomite mudstone is mainly developed structure fractures and dissolution pores, cracks, corrosion in the study area, which is mainly produced by fault activity and caused fluid exchange, acidic fluid dissolved mineral which early replacement by dolomite to produce the solution pores and slot hole network, so this type of reservoir development near in deep big faults, most of this kind reservoir are updip fault block reservoir. Regional development lenticular reservoir that solution porosity as main reservoir space. For dolomite mudstone reservoiring characteristics,in order to find effective reservoir, should be highlighted near the fault where the dolomite mudstone have a good distribution.The research shows that the reservoir physical properties is controlled by the tectonism macrocosmically, while mainly controlled by the diagenesis vertically, which mainly determines the reformation degree of the original pore of the reservoir and the development degree of the secondary pore, while mainly influenced by the sedimentation on the plane, which determines the development of the original pore. Based on the comprehensive analysis of the influence of physical property by the depositional conditions, diagenesis evolution and the tectonism, and the regular pattern of physical properties characteristics and pore distribution.Based on the above research, we make a prediction of the favorable zones respectively to clastic rock reservoir of the gentle slope belt in southern and dolomitic mudstone reservoir in north steep slope zone.The main reservoir types in study area are fault block reservoir and lithologic reservoir, the development of advantages area is near the southern steep slope belt of the gentle slope zone; North steep slope belt is self—generated reservoir of the dolomite mudstone which is mainly distribute in the north steep slope zone near the fault zone of lake basin drop plate, on the horizon are mainly distribute on ts3sand group.
Keywords/Search Tags:Baiyinchagan depression, Tenger formation, petrologicalcharacteristics, reservoir characteristics, fracture-cave reservoir
PDF Full Text Request
Related items