scholarly journals Sedimentary Characteristics Analysis and Sedimentary Facies Prediction of Jurassic Strata in the Northwest Margin of Junggar Basin—Covering the W105 Well Region in the Wuerhe Area

Minerals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 68
Author(s):  
Shiqi Liu ◽  
Yuyang Liu
Keyword(s):  
Cross Sections ◽  
Oil And Gas ◽  
Junggar Basin ◽  
Sedimentary Facies ◽  
Delta Front ◽  
Delta Plain ◽  
Fan Delta ◽  
Single Well ◽  
Northwest Region ◽  
Sand Bodies

As the northwestern area of the Junggar Basin is a key area for oil and gas exploration, the sedimentary facies of the Jurassic formations in the Wuerhe area has long been a focus of research. The target strata are Jurassic strata, including five formations: the Lower Jurassic Badaowan and Sangonghe, the Middle Jurassic Xishanyao and Toutunhe and the Upper Jurassic Qigu. Disputes over the are sedimentary facies division exist in this area. Considering the W105 well region in this area as an example, the overall sedimentary facies of single-well logging facies is analyzed and then expanded to two cross-sections and characterized. Based on previous studies, a detailed overview of the regional stratigraphy is obtained by well logs and other data. Then, two cross-sections are selected and analyzed. The single-well and continuous-well facies of 10 wells in the sections are analyzed to grasp the sand bodies’ spatial distribution. Finally, a planar contour map of the net to gross ratio is mapped to analyze the sources and the distribution of the sand bodies in each period. The sedimentary facies map is also mapped to predict the sedimentary evolution. The results show that the sedimentary facies of the Badaowan Formation in the study area was an underwater distributary channel of the fan-delta front, and the sand body spread continuously from northwest to southeast. The Sangonghe Formation entered a lake transgression period with a rising water level, at which time shore–shallow lacustrine deposits were widespread throughout the region. The period of the Xishanyao Formation entered a regression period, the northwest region was tectonically uplifted, and the central and southeastern regions facies were dominated by the fan-delta front and shallow lacustrine. During the Toutunhe Formation period, the northwest region continued to uplift and was dominated by delta plain facies. During the period of the Qigu Formation, the thickness of stratigraphic erosion reached its maximum, and the non-erosion area of the study area was mainly deposited by the fan-delta plain. Overall, the Jurassic system in the W105 well area is a fan delta–lacustrine–fan delta sedimentary system.

scholarly journals Fine description of sedimentary system in Wuerxun Sag of Hailaer Basin

2020 ◽  
Vol 194 ◽  
pp. 05048
Author(s):  
ZHOU Yue ◽  
GAO Geng ◽  
WANG Duanyang ◽  
YANG Xu
Keyword(s):  
Large Scale ◽  
Oil And Gas ◽  
Sedimentary Facies ◽  
Key Factors ◽  
Oil And Gas Exploration ◽  
Fan Delta ◽  
Sedimentary System ◽  
Sedimentary Microfacies ◽  
Surrounding Areas ◽  
Sand Bodies

Wuerxun depression is one of the depressions with great exploration potential in Hailaer Basin and has submitted large-scale reserves. At present, it has entered the stage of fine exploration, and the exploration object has changed from structural reservoir to lithologic reservoir exploration. The remaining targets are mainly concentrated in the trough and surrounding areas, with strong concealment and difficult to identify. Fine identification of sand bodies, genesis, types and distribution of sedimentary fans are one of the key factors restricting oil and gas exploration. Based on core observation and genetic mechanism, three sedimentary facies models of Braided River Delta, fan delta and sublacustrine fan are established. In this paper, the method of “sequence control, cycle correlation and hierarchical closure” is used to fine characterize the fan delta sedimentary system in this area, which lays a foundation for the study of sedimentary microfacies of subdivision layers, optimization of lithologic reservoir targets and guidance of oil and gas exploration deployment.

scholarly journals Sedimentary Facies of the Chang 2 Member of Yanchang Formation in Area A of Northern Shaanxi

2021 ◽  
Vol 290 ◽  
pp. 02012
Author(s):  
Yingzhi Liu ◽  
Yanyan Liu ◽  
Ying Chen ◽  
Shasha Yang ◽  
Bowang Wang
Keyword(s):  
Sedimentary Facies ◽  
Stratigraphic Correlation ◽  
Sequence Stratigraphic ◽  
Delta Plain ◽  
Base Level ◽  
Sand Body ◽  
Single Well ◽  
Northern Shaanxi ◽  
Core Description ◽  
Sand Bodies

In order to promote the rolling exploration and development of oil reservoirs in northern Shaanxi, a fine study of sedimentary facies in area A has been carried out. Using core and logging data, on the basis of identifying different levels of sequence interfaces and lake flooding, the Chang 2 Member in Area A was divided into two base level cycles, and a high-resolution sequence stratigraphic correlation was established. On the basis of core description, the analysis of single-well sedimentary facies, continuous-well sedimentary facies and planar sedimentary facies are carried out. It is believed that the Chang 2 member of the study area is a delta plain deposit, dominated by distributary channels, inter-distributary depressions, and natural dike microfacies. There are two to three main rivers in the study area. Both the vertical and the plane show that the length of Chang 22 sand bodies is more developed than the length of Chang 21 sand bodies. Among the three small layers of Chang 22, Chang 221 sand body is relatively well developed, and the channel width and thickness are large, making it the most favorable reservoir.

scholarly journals Feldspar Dissolution and Its Influence on Reservoirs: A Case Study of the Lower Triassic Baikouquan Formation in the Northwest Margin of the Junggar Basin, China

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Meng Xiao ◽  
Xuanjun Yuan ◽  
Dawei Cheng ◽  
Songtao Wu ◽  
Zhenglin Cao ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Physical Property ◽  
Junggar Basin ◽  
Sedimentary Facies ◽  
Lower Triassic ◽  
Depositional Environments ◽  
Source Rocks ◽  
Reservoir Quality ◽  
Delta Plain ◽  
Feldspar Dissolution

Feldspar dissolution is a common feature in clastic rock reservoirs of petroliferous basins and has an important influence on reservoir quality. However, the effect of feldspar dissolution on reservoir quality varies under different depositional environments and diagenetic systems. The study area in this paper is located in the Baikouquan Formation in the northwestern margin of the Junggar Basin, which is significantly influenced by feldspar dissolution. Based on the analyses of core and thin section observations, QEMSEM, XRD, SEM, CL, fluorescence, and image analysis software combined with logging and physical property data, this study shows that feldspar dissolution in the subaqueous distributary channel of a fan delta plain, which has good original physical properties and low mud contents, significantly improves the properties of the reservoir. The main reasons for this are as follows: (1) the sedimentary facies with good original properties and low mud content is a relatively open system in the burial stage. The acidic fluids needed for feldspar dissolution are mostly derived from organic acids associated with the source rocks and migrate to the good-permeability area of the reservoir; (2) the by-products of feldspar dissolution, such as authigenic clay minerals and authigenic quartz, are transported by pore water in a relatively open diagenetic system and then precipitated in a relatively closed diagenetic system; and (3) the clay minerals produced by feldspar dissolution in different diagenetic environments and diagenetic stages have different effects on the reservoir. When the kaolinite content is less than 3%, the illite content is less than 4%, and the chlorite content is less than 12%, the clay minerals have a positive effect on the porosity. These clay minerals can reduce porosity and block pore throats when their contents are larger than these values.

Sedimentary Facies and Evolution of early Cretaceous in the Fault Depressions, Songnan Area

2012 ◽  
Vol 152-154 ◽  
pp. 1036-1040
Author(s):  
Ya Sheng Wu ◽  
Da Kang Zhong ◽  
Nan Sheng Qiu ◽  
Xiao Ying Zhang
Keyword(s):  
Structural Geology ◽  
Seismic Data ◽  
Oil And Gas ◽  
Sedimentary Facies ◽  
The Other ◽  
Well Logs ◽  
Sedimentary Environments ◽  
Sedimentary Evolution ◽  
Fan Delta ◽  
Two Stages

Based on the structural geology, sedimentology, palaeontology and geochemistry, the sedimentary facies and evolution patterns are developed in Songnan area from the studies of seismic data, cores, well logs, palaeontology and geochemistry. The result indicates that nearshore subaqueous fan, fan delta, braid delta and lacustrine had been developed in the fault depressions of Songnan area. From the margin to the depocenter of the basin, the sedimentary environments gradually changed from nearshore subaqueous fan, fan delta or braid delta to shore-shallow sediments and middle depth-deep lacustrine. Two stages are divided for the sedimentary evolution of Songnan area, namely the prior stage which appears with Yixian formation developing lava facies and pyroclastic facies; the other is the detrital rock facies ,which are developed from formation Jiufotang to Fuxin, is composed of nearshore subaqueous fan, fan delta, braid delta and lacustrine. Conclusion can be made that those sedimentary facies are controlled by the depth of water variation, which changed from shallow to deep, and then to shallow. Multiple source-reservoir-cap assemblage in vertical provided favourable condition for oil and gas pool forming.

The Application of Facies Modeling Combination of Well Data and Seismic Data in G25-12 Block

2015 ◽  
Vol 733 ◽  
pp. 92-95
Author(s):  
Jia Hui Wang ◽  
Hong Sheng Lv
Keyword(s):  
Sedimentary Facies ◽  
Distribution Law ◽  
Skeleton Model ◽  
Facies Model ◽  
Body Distribution ◽  
Sand Body ◽  
Geological Conditions ◽  
Single Well ◽  
Well Data ◽  
Sand Bodies

The main purpose of lithofacies modeling is to get the actual reservoir lithofacies skeleton model which is maximum approximation of the underground reservoir. The facies model can effectively solve the problem of predicting sand bodies between wells. At the same time, we still use the stochastic modeling method to build the facies model of unconstrained single well simulation and sedimentary facies controlled constrained simulation. We elected the model which is most consistent to the actual geological conditions, providing theoretical guidance for characterizing the interwell sand body distribution law and improving the accuracy of predicting sand bodies between wells, laiding the foundation for further exploration and development of oil reservoir.

scholarly journals Sedimentary system and coal seam distribution in the coal-bearing sequence stratigraphic framework in the Paleogene Meihe Formation (Meihe Basin, NE China)

2020 ◽  
Author(s):  
Yueyue Bai ◽  
Qingtian Lv ◽  
Zhaojun Liu ◽  
Pingchang Sun ◽  
Rong Liu ◽  
...  
Keyword(s):  
Coal Seam ◽  
Accumulation Rate ◽  
Mapping Method ◽  
Sediment Supply ◽  
Coal Seams ◽  
Delta Front ◽  
Contour Maps ◽  
Delta Plain ◽  
Fan Delta ◽  
Wide Range

Abstract The Meihe Basin is one of the important Paleogene coal-bearing fault basins of northeastern China in the Dunhua-Mishan Fault Zone. The Lower Coal-bearing Member and the Upper Coal-bearing Member are the primary layers studied. Through field observation, core description and observation under microscope, fan delta facies and lake facies are observed as the main sedimentary facies of the coal-bearing layers, and subfacies of fan delta plain, fan delta front, shallow lake and swamp have also been recognized. Coal seams primarily accumulated in the subfacies of swamp and fan delta plain. The study on sequence stratigraphy is based on outcrop section, well-log analysis, core observation and geochemical analysis. From the Lower Coal-bearing Member to the Upper Coal-bearing Member, three third-order sequences have been recognized; the Lower Coal-bearing Member developed in Sequence I and the Upper Coal-bearing Member developed in Sequence III, both sequences have developed the lowstand systems tract (LST), the transgressive systems tract (TST) and the highstand systems tract (HST). Single-factor analysis and the multifactor comprehensive mapping method have been used to rebuild the lithofacies palaeogeography of each system tract in Sequence I and Sequence III. Through analysis of contour maps of total stratum thickness, sandstone thickness and sand content, as well as contour maps of thicknesses and numbers of layers of coal seams, the results indicate that the sedimentary environments and coal seam distributions are variable in different system tracts. Coal types accumulating in the swamp facies are primarily developed in the transgressive systems tract (TST) and the highstand systems tract (HST) of Sequence I with a wide range of continuous and large thicknesses and may be mined commercially. Both the balanced accommodation growth rate with peat accumulation rate and little or no influence from sediment supply and channel migration promote to form the stable coal accumulating environments.

The Types of Sedimentary Facies and Rock Characteristics of Xujiaweizi Fault Depression in Songliao Basin

2013 ◽  
Vol 787 ◽  
pp. 717-720
Author(s):  
Cheng Zhi Liu ◽  
Xue Du ◽  
Xiao Zhou ◽  
Bo Li ◽  
Xi Liu
Keyword(s):  
Main Type ◽  
Sedimentary Facies ◽  
Songliao Basin ◽  
River Delta ◽  
Braided River ◽  
Delta Front ◽  
Braided Channel ◽  
Fan Delta ◽  
Sedimentary System ◽  
Lacustrine Facies

In the Shahezi Formation of Xujiaweizi fault depression in the Songliao Basin mainly tow sedimentary system is developed: the Xudong gentle slope belt and Xuxi fault zone systems. However, this area is little studied as there have been only limited efforts in exploration. Based on the latest drilling, outcrop data, description of core observation and laboratory microscope identification, it has been concluded that four mainly sedimentary facies are developed in this area: braided river delta, fan delta, lacustrine facies and sublacustrine fan. The subaqueous distribute channel is the main type of the fan delta front while the braided channel is the main type of the braided river delta. A number of clastic, sandstone and mudstone are developed in these two types of sedimentary facies. We can use it to make further study of dividing into micro-facies.

Controls of Short-Term Base-Level Cycle on Macroscopic Heterogeneity of Reservoir: a Case Study of the Major Oil Layer of Liuzan Oilfield in Nanpu Sag

2011 ◽  
Vol 347-353 ◽  
pp. 56-59
Author(s):  
Rui Zhang ◽  
You Liang Ji
Keyword(s):  
Short Term ◽  
Delta Front ◽  
River Sand ◽  
Significant Control ◽  
Plain Area ◽  
Delta Plain ◽  
The Third ◽  
Base Level ◽  
Fan Delta ◽  
Nanpu Sag

Based on the depositional model and characteristics of fan delta, the short-term base-level cycle of the third submember of the third member of Shahejie Formation （Es33）in North region major oil layer of Liuzan Oilfield of Nanpu Sag is divided into three basic categories applying high-resolution sequence stratigraphy with the reference to core and logging data, namely, deepening-upward asymmetrical type, shallowing-upward asymmetrical type and symmetrical type. Different variation models for macroscopic heterogeneity of reservoir belonging to different categories of short-term base-level cycle were established in this paper; it was further pointed out that the changes of base-level and the ancient landform were major factors controlling the characteristic discrepancy of macroscopic heterogeneity of reservoir. In fan delta plain area, the ancient landform is smooth. Deepening-upward asymmetrical cycle is mainly composed of braided river sand body, and the changes of base-level exert little control on porosity with significant control on permeability. At the delta front slope, the landform becomes steep. Deepening-upward asymmetrical cycle is mainly composed of underwater distributary channel with genetic mechanism of gravity flow. The vertical variations of porosity and permeability inside the cycle are rather complicated. Since the physical properties are mainly manifested as the control on autogenic cycle, they do not directly influence the changes of base level.

Research on Sedimentary Microfacies of Sandstone Group I in Putaohua Oil Reservoir of Gu83 Block in Gulong Oilfield

2013 ◽  
Vol 787 ◽  
pp. 618-621
Author(s):  
Yang Liu ◽  
Cheng Zhi Liu ◽  
Hui Li ◽  
Xiao Jing Liu ◽  
Yu Cong Li
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Delta Front ◽  
Group I ◽  
Core Logging ◽  
Work Area ◽  
Sedimentary Microfacies ◽  
Plane Distribution ◽  
Drilling Core ◽  
Sand Bodies

The oil and gas reserves of Gu83 block in Gulong oilfield is very abundant, but the development is very difficult because the sand bodies are thin, scattered and lack of horizontal continuity. Guided by the theory of sequence stratigraphy and reservoir sedimentology, using drilling core, logging and seismic data, the researcher found that the interest area belongs to delta front subfacies deposition, which can be mainly classified by four miscrofacies types including underwater distributary channel, mouth, sheet sand and bay between distributary. The plane distribution of sedimentary microfacies are mainly controlled by the west and north provenance, the two source collected in the middle east of the work area.

Sedimentological signatures and identification of Paleocene sedimentary facies in the Lishui Sag, East China Sea Shelf Basin

2020 ◽  
Vol 57 (3) ◽  
pp. 377-395 ◽  
Author(s):  
Zhongqiang Sun ◽  
Jinliang Zhang ◽  
Yang Liu ◽  
Wenlong Shen ◽  
Yang Li ◽  
...  
Keyword(s):  
East China Sea ◽  
Sedimentary Facies ◽  
East China ◽  
The East China Sea ◽  
Delta Front ◽  
China Sea ◽  
Fan Delta ◽  
East China Sea Shelf ◽  
Sand Sheet ◽  
Sand Bar

The Lishui Sag is on the southwest margin of the East China Sea Shelf Basin (ECSSB), which is located on the continental shelf of the East China Sea. The analysis of sedimentological signatures is based on 217 m (712 ft) of Paleocene cores showing a wide variety of lithofacies, sedimentary structures, ichnological data, seismic data, and log data. Eight lithofacies, nine typical ichnofabrics, and four ichnofacies combined with petrological, geophysical, and bioturbation information were identified as the key sedimentary facies characteristics for identifying three sedimentary systems in the study area. Eleven sedimentological facies are present in the three sedimentary systems: foreshore, upper shoreface, lower to middle shoreface, offshore transition, proximal fan delta front, distal fan delta front, wave-dominated delta front sand bar, wave-dominated delta front sand sheet, interbar, tide-influenced distributary channel, and tide-influenced interdistributary bay facies. The three sedimentary systems that were identified are fan delta, wave-influenced delta, and tide facies. Fan delta deposits are present in the southwest and northeast of the sag, with subaqueous fan delta front deposits dominating, whereas farther seaward successions are characterized by distal fan delta front deposits that are intensely bioturbated. Wave-dominated deltaic deposits occur mostly in the western and middle parts, where fluvial discharge in the delta front and prodelta have been repeatedly reworked by waves and formed some isolated bars distributed perpendicular to the source; these deposits are sparsely to intensely bioturbated. Tide facies develop locally and have been identified as distributary channels and interdistributary bay facies.

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