Research on the lithofacies and paleogeography of the lower Cambrian Xiaoerbulake Formation in the northern Tarim Basin, northwestern China

Based on the study of cores, thin sections, and outcrops, the sedimentary facies of the lower Cambrian carbonate rocks in the northern Tarim Basin can be divided into four types: restricted platform, open platform, ramp, and basin. Based on the lithologic analysis of thin sections, two-dimensional seismic data interpretation, and an isopach map of the lower Cambrian Xiaoerbulake Formation in the study area, seven sedimentary facies of carbonate rocks were identified, including inner platform depression, shoal, intershoal sea, platform margin, gypsum salt lake, ramp, and basin. The depositional model of the lower Cambrian Xiaoerbulake Formation in the northern Tarim Basin is constructed based on this integrated research. The topset, foreset, and bottomset of oblique progradational reflections are interpreted as the platform margin beach, ramp, and basin environments, respectively. The thicker area with micritic dolomite as the dominant lithology is interpreted as a platform depression. The low-amplitude hummocky reflections are interpreted as shoals that consist of a variety of granular dolomite and algal dolomite. The thinner uplifted area with gypsum and dolomite present in cores is interpreted as a restricted platform with a gypsiferous dolomite tidal flat or lake environment. Well LT1, which was drilled recently in the platform margin and ramp region, as indicated by seismic progradational clinoform reflections, has produced high yields of oil and gas. Supported by the above research results, the map of the lithofacies and paleogeography of the Xiaoerbulake Formation in the northern Tarim Basin was recompiled.

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Depositional, diagenetic and stratigraphic aspects of Macaé Group carbonates (Albian): example from an oilfield from Campos Basin

Brazilian Journal of Geology ◽

10.1590/23174889201500020005 ◽

2015 ◽

Vol 45 (2) ◽

pp. 243-258 ◽

Cited By ~ 11

Author(s):

Juliana Okubo ◽

Ricardo Lykawka ◽

Lucas Veríssimo Warren ◽

Julia Favoreto ◽

Dimas Dias-Brito

Keyword(s):

Deep Water ◽

Carbonate Rocks ◽

Facies Analysis ◽

Sedimentary Facies ◽

Fair Weather ◽

Thin Sections ◽

Carbonate Sedimentation ◽

Diagenetic Processes ◽

Campos Basin ◽

Facies Associations

<p>Carbonate rocks from the Macaé Group (Albian) represent an example of carbonate sedimentation related to the drift phase in Campos Basin. This study presents depositional features, integrating them with diagenetic and stratigraphic aspects of the Macaé Group carbonates including the upper part of the Quissamã Formation and the lower part of the Outeiro Formation. Macroscopic analyses in cores and microscopic ones in thin sections allowed the recognition of eleven sedimentary facies - nine of them corresponding to the Quissamã Formation and two of them representing the Outeiro Formation. These facies were grouped into five facies associations. Oolitic grainstones and oncolitic grainstones are interpreted to be deposited in shallow depth probably in shoals above the fair weather wave base. The interbanks between shoals were formed in less agitated waters and characterized by deposition of peloidal bioclastic packstones and wackestones representative of sedimentation in calm waters. Bioclastic packstones and oolitic packstones/wackestones represent allochthonous deposits related to the beginning of the regional drowning that occur in upper Quissamã Formation. Pithonellids wackestones and bioclastic wackestones with glauconite are related to deep water deposits, characteristics of the Outeiro Formation. Post-depositional features revealed the action of diagenetic processes as, micritization, cimentation, dissolution, compaction, dolomitization and recrystallization occurred during the eo- and mesodiagenesis phases. Vertical facies analysis suggests shallowing upward cycles stacked in a sequence progressively deeper towards the top (from the Quissamã Formation to the Outeiro Formation).</p>

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Characterization and discrimination of paleokarst breccias and pseudobreccias in carbonate rocks: Insight from Ordovician strata in the northern Tarim Basin, China

Sedimentary Geology ◽

10.1016/j.sedgeo.2019.01.007 ◽

2019 ◽

Vol 382 ◽

pp. 61-74 ◽

Cited By ~ 4

Author(s):

Qilong Fu

Keyword(s):

Tarim Basin ◽

Carbonate Rocks ◽

Northern Tarim Basin

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Hydrothermal Dissolution of Deeply Buried Cambrian Dolomite Rocks and Porosity Generation: Integrated with Geological Studies and Reactive Transport Modeling in the Tarim Basin, China

Geofluids ◽

10.1155/2017/9562507 ◽

2017 ◽

Vol 2017 ◽

pp. 1-19 ◽

Cited By ~ 5

Author(s):

Wenwen Wei ◽

Daizhao Chen ◽

Hairuo Qing ◽

Yixiong Qian

Keyword(s):

Tarim Basin ◽

Carbonate Rocks ◽

Reactive Transport ◽

Wall Rock ◽

Transport Modeling ◽

Reactive Transport Modeling ◽

Fluid Temperature ◽

Upward Migration ◽

Vertical Permeability ◽

Northern Tarim Basin

The burial dissolution of carbonate rocks has long been an interesting topic of reservoir geologists. Integrated with geological studies and reactive transport modeling, this study investigated the Cambrian dolomites that were buried at depths up to 8408 m and still preserved a large amount of unfilled dissolution vugs from the borehole TS1 in the northern Tarim Basin. Studies indicate that these vugs were formed in association with fault-channeled hydrothermal fluids from greater depth through “retrograde dissolution” as the fluid temperature dropped during upward migration. The reactive transport modeling results suggest an important control of the vertical permeability of wall-rock on fluid and temperature patterns which, in turn, would control the spatial distribution of dissolving-originated porosity. The hydrothermal dissolution mainly occurred in dolomite wall-rocks with higher vertical permeability (extensive development of tensional fractures and connected pore spaces), producing additional dissolved porosity there during deep burial. This study implicates the importance of multidisciplinary approaches for understanding the burial/hydrothermal dissolution of dolomite rocks and predicting favourable deep/ultradeep carbonate reservoirs.

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Cambrian Ordovician sedimentary facies and its evolution in Tadong area

E3S Web of Conferences ◽

10.1051/e3sconf/202132901055 ◽

2021 ◽

Vol 329 ◽

pp. 01055

Author(s):

Ding Hansheng

Keyword(s):

Oil And Gas ◽

Carbonate Platform ◽

Sedimentary Facies ◽

Seismic Profile ◽

Oil And Gas Exploration ◽

Stratigraphic Framework ◽

Lower Ordovician ◽

Platform Margin ◽

Carbonate Platform Margin ◽

Order Sequence

In order to clarify the sedimentary development law under the Cambrian Ordovician regional stratigraphic framework in Tadong area, and lay a theoretical foundation for further oil and gas exploration in the study area. The distribution, characteristics and evolution of main sedimentary facies belts of Cambrian Ordovician are studied by means of drilling core observation, cast thin section identification, logging curve feature analysis, seismic profile and well connection profile. The results show that the Cambrian middle lower Ordovician in Tadong area is equivalent to a second-order sequence and can be further divided into 12 thirdorder sequences. Each third-order sequence is mainly composed of transgressive and highstand tracts. Carbonate platform margin beach facies and Reef (mound) beach complex facies are favorable reservoir development facies belts in this area; Under the regional stratigraphic framework, three types of sedimentary facies can be identified in Cambrian Ordovician, and a total of 10 subfacies are developed; The evolution of sedimentary facies is mainly controlled by the rise and fall of sea level, which is characterized by the migration of platform margin facies and the change of platform facies.

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Emplacement of intrusions of the Tarim Flood Basalt Province and their impacts on oil and gas reservoirs: A 3D seismic reflection study in Yingmaili fields, Tarim Basin, northwest China

Interpretation ◽

10.1190/int-2016-0165.1 ◽

2017 ◽

Vol 5 (3) ◽

pp. SK51-SK63 ◽

Cited By ~ 4

Author(s):

Zhongbo Gao ◽

Wei Tian ◽

Lei Wang ◽

Yongmin Shi ◽

Mao Pan

Keyword(s):

Tarim Basin ◽

Seismic Reflection ◽

Oil And Gas ◽

Northwest China ◽

Lower Permian ◽

Magmatic Activity ◽

3D Seismic ◽

Gas Reservoirs ◽

Oil And Gas Reservoirs ◽

Northern Tarim Basin

A basaltic dike-sill network is emplaced into the shallow subsurface of the Yingmai-2 dome, northern Tarim Basin, northwest China. The 3D seismic reflection imaging suggests that these dikes and sills are fed from an intrusion at the focal area of the dome. This basaltic intrusion has a width of approximately 3000 m and thickness of approximately 1000 m, and it is connected with a much larger Early Permian igneous body in the northern Tarim Basin. An unconformity between the Permian basalt lava flows and the base Triassic conglomerates truncates the dome, meaning that the dome must have developed prior to the Triassic. The basaltic intrusion that emplaced beneath the dome likely pushed the surrounding middle Cambrian salts away and instigated uplift of the overlying upper Cambrian to the lower Permian strata. In most cases, igneous activity plays a negative role on formation of oil and gas reservoirs. However, in the Yingmai-2 case, intrusive magmatic activity has caused “forced folding” of the overburdened strata and controlled the formation of a large commercial oil trap. We suggest that the magmatic activity thus also acts as a positive role on the local formation of a producing petroleum system.

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Structure characteristics and major controlling factors of platform margin microbial reef reservoirs: A case study of Xiaoerbulak Formation, Lower Cambrian, Aksu area, Tarim Basin, NW China

Petroleum Exploration and Development ◽

10.1016/s1876-3804(17)30044-7 ◽

2017 ◽

Vol 44 (3) ◽

pp. 377-386 ◽

Cited By ~ 3

Author(s):

Ying BAI ◽

Ping LUO ◽

Shi WANG ◽

Chuanmin ZHOU ◽

Xiufen ZHAI ◽

...

Keyword(s):

Tarim Basin ◽

Lower Cambrian ◽

Controlling Factors ◽

Nw China ◽

Structure Characteristics ◽

Platform Margin

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High Resolution Sequence Stratigraphy Characteristics and Distribution of Donghe Sandstone in Qunkuqiake Region in Tarim Basin

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1044-1045.570 ◽

2014 ◽

Vol 1044-1045 ◽

pp. 570-573

Author(s):

Mu Wei Cheng

Keyword(s):

Tarim Basin ◽

High Frequency ◽

Oil And Gas ◽

Sedimentary Environment ◽

Sedimentary Facies ◽

Sequence Stratigraphic ◽

Sedimentary Characteristics ◽

Sand Body ◽

Frequency Sequence ◽

High Resolution Sequence Stratigraphy

Qunkuqiake Region is an important exploration block in Tarim Basin. Donghe Sandstone is the main oil and gas target stratum. In order to reveal the rules of migration of the sand body and predict the favorable reservoir accurately, two high-frequency cycles are identified in Donghe Sandstone each of which consists of rising hemicycle and descending hemicycle, the sedimentary characteristics are analysed within the sequence stratigraphic framework and the barrier bar subfacies are identified beginning with the sedimentary characteristics of glutenite through the study of drilling stratigraphic section using drilling data, well logging data and cores data. This paper has disclosed the transition of the sedimentary environment from barrier-free coast system to barrier coast system during the period from rising hemicycle to descending hemicycle and the planar distribution of sedimentary facies of different high frequency sequence of Donghe Sandstone.

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Study on Fracture Characteristics and Controlling Factors of Tight Sandstone Reservoir: A Case Study on the Huagang Formation in the Xihu Depression, East China Sea Shelf Basin, China

Lithosphere ◽

10.2113/2021/3310886 ◽

2021 ◽

Vol 2021 (Special 1) ◽

Author(s):

Zhongxiang Zhao ◽

Youbin He ◽

Xin Huang

Keyword(s):

Oil And Gas ◽

Fractured Reservoirs ◽

Particle Morphology ◽

Sedimentary Facies ◽

Identification Accuracy ◽

Historical Period ◽

Natural Fractures ◽

High Angle ◽

Tight Sandstone ◽

Thin Sections

Abstract Natural fractures are not only the key to affect the natural productivity of tight sandstone reservoirs but also one of the important factors to control the fracturing effect. If the local strata are affected by multistage tectonic movement and diagenesis, it will lead to the complexity of fracture types and characteristics, which makes it difficult to accurately identify natural fractures, thus, seriously affect the development of fractured reservoirs and the fracturing effect. In this paper, the macroscopic fractures were studied by combining core, conventional logging, imaging logging, petrophysical logging, logging, drilling, and gas test data. The microscopic fractures were analyzed by casting thin sections and scanning electron microscopy and cathodoluminescence. The effect of fractures on hydrocarbon migration was analyzed by fluid inclusions in fractures. The core can be used to visually study the opening fracture, but when the color of the filling inside the fracture is similar to the surrounding, the filling fracture is not easy to be found. Imaging logging has high identification accuracy for filling fractures, but it can hardly be used as a means of identifying high-angle opening fractures. The opening fracture zone in the noncoring section can be studied by conventional logging, mud logging, drilling, and rock mechanical parameter. The macroscopic structural fractures are obviously directional, which is controlled by the tectonic stress field. The occurrence and density of macroscopic structural fractures are controlled by buried depth, lithology, rock thickness, sedimentary facies, distance from the fault, and structural location. The opening fractures are all of high angle, indicating that the inclination angle is an important factor affecting the filling degree of fractures. The direction of intragranular fractures is chaotic, which is affected by the mechanical weak surface of the mineral particles, particle morphology, and particle contact relationship and stress. Effective fractures provide channels for the migration of oil and gas and acidic fluids in the historical period, which promote the occurrence of hydrocarbon accumulation and dissolution.

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Hydrothermal-metasomatic systems as the most important factor for the formation of elements of the oil and gas-bearing complex in the Bazhenov-Abalak sediments

Georesursy ◽

10.18599/grs.2021.2.14 ◽

2021 ◽

Vol 23 (2) ◽

pp. 142-151

Author(s):

Evgenia V. Karpova ◽

Aleksey O. Khotylev ◽

Ekaterina A. Manuilova ◽

Aleksandr A. Mayorov ◽

Elizaveta A. Krasnova ◽

...

Keyword(s):

Carbonate Rocks ◽

Oil And Gas ◽

Pore Space ◽

Structural Elements ◽

Mineral Formation ◽

Reservoir Properties ◽

Thin Sections ◽

The Impact ◽

Gas Bearing ◽

Scanning Electron

A model of the activity of hydrothermal-metasomatic systems confined to certain structural elements is proposed in the present article. The model is based on the analysis of a large volume of traditional studies: measurements of porosity coefficients, permeability, pyrolytic measurements - together with specific measurements: isotopic composition of carbonate rocks, temperature of homogenization of gas-liquid inclusions, studies of the composition of rocks with a scanning electron microscope, a description of petrographic thin sections. The model allows to generalize the results of the impact of hydrothermal-metasomatic systems on the reservoir properties of the rocks of the Bazhenov-Abalak complex: constructive – leaching processes and increasing reservoir properties, and destructive – massive mineral formation that fills the pore space, up to the formation of secondary seals.

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