scholarly journals Multiphase Calcite Cementation and Fluids Evolution of a Deeply Buried Carbonate Reservoir in the Upper Ordovician Lianglitag Formation, Tahe Oilfield, Tarim Basin, NW China

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Jiaqing Liu ◽  
Zhong Li ◽  
Lijuan Cheng ◽  
Jiawei Li
Keyword(s):  
Fluid Inclusion ◽  
Tarim Basin ◽  
Meteoric Water ◽  
Oil And Gas ◽  
Isotope Analysis ◽  
Carbonate Reservoir ◽  
Upper Ordovician ◽  
Nw China ◽  
Tahe Oilfield ◽  
Homogenization Temperatures

Oil and gas have been found in the Upper Ordovician Lianglitag Formation carbonates in the Tahe Oilfield, Tarim Basin, NW China. This study documents the origin of diagenetic fluids by using a combination of petrology, SIMS, fluid inclusion, and radiogenic isotope analysis. Six stages of calcite cements were revealed. C1-C2 formed in marine to early burial environments. C3 has relatively low δ18OVPDB values (−8.45‰ to −6.50‰) and likely has a meteoric origin. Meteoric water probably fluxed into aquifers during the Early Paleozoic and Late Paleozoic uplift. C4 has δ18OVPDB values typically 3‰ higher than those of C3, and probably formed during shallow burial. C5 displays relatively negative δ18OVPDB values (−8.26‰ to −5.12‰), and the moderate-to-high fluid-inclusion temperatures imply that it precipitated in burial environments. C6 shows homogenization temperatures (up to 200°C) higher than the maximum burial and much lower salinities (<10.61 wt% NaCl), which may suggest that the fluid was deeply recycled meteoric water. The average 87Sr/86Sr ratios of fracture- and vug-filling calcite cements are much higher, indicative of incorporation of radiogenic Sr. Caves and fractures constitute the dominant reservoir spaces. A corresponding diagenesis-related reservoir evolution model was established that favors exploration and prediction.

Determination of oil charge timing in the Ordovician carbonate reservoir of the Tahe Oilfield, Tarim Basin, NW China

2021 ◽  
Author(s):  
Jiaxu Chen ◽  
Xiaowen Guo
Keyword(s):  
Tarim Basin ◽  
Sedimentary Basins ◽  
Carbonate Reservoir ◽  
Rock Interaction ◽  
Tahe Oilfield ◽  
Petroleum Systems ◽  
Calcite Veins ◽  
Homogenization Temperatures ◽  
Two Phases ◽  
Northern Tarim Basin

&lt;p&gt;Determining the timings of oil charge in sedimentary basins are essential to understand the evolutionary histories of petroleum systems, especially in sedimentary basins with complicated tectonic evolution and thermal histories. The Ordovician carbonate reservoir in the Tahe Oilfield, which is located in the northern Tarim Basin, comprises the largest marine reservoirs in China with reserves up to 3.2&amp;#215;10&lt;sup&gt;8&lt;/sup&gt; t. This study aims to determine the timings of oil charge in the Ordovician carbonate reservoir in the Tahe Oilfield, Tarim Basin, which basin is subjected to multiple phases of tectonic deformations and oil charge. The phases of calcite veins that contain oil inclusions were systematically investigated by cathodoluminescence observation, in situ rare earth element, C, O, and Sr isotope analyses. The homogenization temperatures of aqueous inclusions that are coeval with oil inclusions were measured to determine the timings of oil charge by combining the burial and geothermal histories. Two phases of calcite veins were judged by the differences in cathodoluminescence color, Ce anomaly, &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O, and &lt;sup&gt;87&lt;/sup&gt;Sr/&lt;sup&gt;86&lt;/sup&gt;Sr values, which might be caused by variations in the water-rock interaction processes during different calcite phases. Primary oil inclusions with yellow fluorescence were observed in the two phases of calcite veins, suggesting two phases of oil charge. By combining the homogenization temperatures of aqueous inclusions with the burial and geothermal histories, the timing of phase I oil charge was inferred to be 336&amp;#8211;312 Ma, and the timing of phase II oil charge was inferred to be 237&amp;#8211;217 Ma.&lt;/p&gt;

Geotemperature Evolution of the Ordovician Strata in the Tarim Basin and its Petroleum Geology Significance

2012 ◽  
Vol 622-623 ◽  
pp. 1638-1641
Author(s):  
Zong Lin Xiao ◽  
Qing Qing Hao ◽  
Zhong Min Shen
Keyword(s):  
Tarim Basin ◽  
Oil And Gas ◽  
Petroleum Exploration ◽  
Upper Ordovician ◽  
Tahe Oilfield ◽  
Oil Resources ◽  
Oil And Gas Resources ◽  
Steady State Heat ◽  
The One ◽  
Oil Cracking

The Tarim basin is an important petroleum basin in China, which produces a large amount of oil and gas resources. This paper calculates the geotemperature of the middle-upper Ordovician basal boundary during the main geological periods using the one-dimensional steady-state heat conduction equation. The simulation result reveals that from the late Ordovician to the present, the Manjiaer sag in the Tabei depression retains the highest temperature in the Tarim basin, and its highest temperature reaches 400°C in the present, while other areas in the Tarim basin have undergone relatively low temperature. Only in the Manjiaer sag of the Tabei depression and the Yecheng and Tanggubasi sags in the Southwest depression, the temperature exceeds 250°C, reaching the condition of liquid oil cracking into gas. Geotemperature of the middle-upper Ordovician basal boundary in the Tahe oilfield of the Central uplift is lower than 250 °C. It is thus inferred that there are abundant oil resources in the Ordovician strata of the Tahe oilfield. This study may provide effective geotemperature data for the next petroleum exploration in the Tarim basin.

Seismic attribute for characterization and prediction of carbonate faulted karst reservoirs in Tarim Basin, China

2021 ◽  
pp. 1-36
Author(s):  
Zhiwei Xiao ◽  
Li Wang ◽  
Ruizhao Yang ◽  
Dewei Li ◽  
Lingbin Meng
Keyword(s):  
Tarim Basin ◽  
Oil And Gas ◽  
Prediction Method ◽  
Strike Slip ◽  
Fault System ◽  
Bright Spot ◽  
Upper Ordovician ◽  
Reservoir Prediction ◽  
Seismic Attribute ◽  
Gas Field

An ultradeep, faulted karst reservoir of Ordovician carbonate was discovered in the Shunbei area of the Tarim Basin. Fractured-cavity reservoirs buried beneath the large thickness of upper Ordovician mudstone were formed along the fault-karst belts. The hydrocarbon accumulation in these reservoirs is controlled by the fault system, and the oil-gas accumulation was affected by karstification and hydrothermal reformation. Previous studies and 2D modeling revealed that the reservoirs had “bright spot” amplitude responses like “string beads,” and they have developed along the strike-slip faults. However, describing such a complex fault-controlled karst system is still a difficult problem that has not been well addressed. We have sought to instruct the attribute expression of faulted karst reservoirs in the northern part of the Tarim Basin. We applied coherence and fault likelihood (FL) seismic attributes to image faults and fractures zones. We then used a trend analysis method to calculate the residual impedance from the impedance of the acoustic inversion, using the fact that residual impedance has higher lateral resolution in reservoir predictions. Finally, we integrated the coherence, FL, and residual impedance attributes into a new seismic attribute, the “fault-vuggy body,” with a certain fusion coefficient. The fault-vuggy body attribute establishes a connection between faults and karst cavities. This method could help in the characterization and prediction of carbonate faulted karst reservoirs. Available drilling data were used to validate that the fused fault-vuggy body attribute was an effective reservoir prediction method. As the seismic sections and slices along the layer help delineate, the distribution of bright spots and strike-slip faults indicates that the main strike-slip fault zones are the most favorable reservoirs in the Shunbei Oil and Gas Field.

scholarly journals Oil charging history and pathways of the Ordovician carbonate reservoir in the Tuoputai region, Tarim Basin, NW China

2017 ◽  
Vol 14 (4) ◽  
pp. 662-675 ◽  
Author(s):  
Rong-Hui Fang ◽  
Mei-Jun Li ◽  
Hai-Tao Lü ◽  
T. -G. Wang ◽  
Yuan Yuan ◽  
...  
Keyword(s):  
Tarim Basin ◽  
Carbonate Reservoir ◽  
Nw China

scholarly journals Fluid Inclusion and Oxygen Isotope Constraints on the Origin and Hydrothermal Evolution of the Haisugou Porphyry Mo Deposit in the Northern Xilamulun District, NE China

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Qihai Shu ◽  
Yong Lai
Keyword(s):  
Fluid Inclusion ◽  
Meteoric Water ◽  
Early Time ◽  
Low Oxygen ◽  
Potassic Alteration ◽  
Low Salinity ◽  
Oxygen Isotopic ◽  
Homogenization Temperatures ◽  
Porphyry Mo Deposit ◽  
Positive Correlations

The Haisugou porphyry Mo deposit is located in the northern Xilamulun district, northeastern China. Based on alteration and mineralization styles and crosscutting relationships, the hydrothermal evolution in Haisugou can be divided into three stages: an early potassic alteration stage with no significant metal deposition, a synmineralization sericite-chlorite alteration stage with extensive Mo precipitation, and a postmineralization stage characterized by barren quartz and minor calcite and fluorite. The coexistence of high-salinity brine inclusions with low-salinity inclusions both in potassic alteration stage (~440°C) and locally in the early time of mineralization stage (380–320°C) indicates the occurrence of fluid boiling. The positive correlations between the homogenization temperatures and the salinities of the fluids and the low oxygen isotopic compositions (δ18Ofluid < 3‰) of the syn- to postmineralization quartz together suggest the mixing of magmatic fluids with meteoric water, which dominated the whole mineralization process. The early boiling fluids were not responsible for ore precipitation, whereas the mixing with meteoric water, which resulted in temperature decrease and dilution that significantly reduced the metal solubility, should have played the major role in Mo mineralization. Combined fluid inclusion microthermometry and chlorite geothermometer results reveal that ore deposition mainly occurred between 350 and 290°C in Haisugou.

scholarly journals Hydrocarbon Distribution Pattern in the Upper Ordovician Carbonate Reservoirs and its Main Controlling Factors in the West Part of Northern Slope of Central Tarim Basin, NW China

2012 ◽  
Vol 30 (5) ◽  
pp. 775-792 ◽  
Author(s):  
Xiuxiang Lü ◽  
Jianfa Han ◽  
Xiang Wang ◽  
Weiwei Jiao ◽  
Hongfeng Yu ◽  
...  
Keyword(s):  
Physical Properties ◽  
Distribution Pattern ◽  
Tarim Basin ◽  
Oil And Gas ◽  
Petroleum Exploration ◽  
Chemical Compositions ◽  
Northern Slope ◽  
Upper Ordovician ◽  
The West ◽  
West Part

The northern slope of Tazhong palaeo-uplift has become a key target field for petroleum exploration in Tarim Basin. A major breakthrough is made in the Upper Ordovician oil and gas exploration in the west part of northern slope. Oil and gas near the Tazhong I slope-break zone occurred in Liang2 section was dominated by condensate gas reservoir, while oil reservoir was mainly inward distributed in Liang3 section. The crude oils in this region in physical properties characterized by low density, low viscosity, low freezing point, low sulfur content, medium wax content. And the natural gas in chemical components was featured by low-medium nitrogen content, low-medium carbon dioxide content and medium-high hydrogen sulfide content. In the plane direction, oil and gas exhibited a “oil in the interior, gas in the exterior” distribution pattern, and mainly located in a depth range of 0∼60 m below the top of the Liang3 section in the longitudinal direction. The distribution patterns displayed in physical properties and chemical compositions of oil and gas are controlled by multiple influencing factors. The results of above comprehensive studies suggested that vertical overriding of reef-bank-type reservoirs in Liang2 section and karst reservoirs in Liang3 section provided superior reservoir conditions; faults and fractures not only formed reservoir space and improved reservoir quality, also promoted the development of karst reservoirs and provided good migration pathway for hydrocarbon accumulation; one of the nonnegligible factors leading to this kind of distribution pattern for the Upper Ordovician oil and gas reservoirs is shale content in the compact carbonate formation; multi-sources and multi-stages of hydrocarbon filling are absolutely necessary controlling factor for this kind of distribution pattern in the whole block.

Clumped isotope geothermometry of an Ordovician carbonate mound, Hudson Bay Basin

2020 ◽  
Vol 178 (1) ◽  
pp. jgs2020-102
Author(s):  
Josué J. Jautzy ◽  
Martine M. Savard ◽  
Denis Lavoie ◽  
Omid H. Ardakani ◽  
Ryan S. Dhillon ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Oil And Gas ◽  
Fission Track ◽  
Hudson Bay ◽  
Apatite Fission Track ◽  
Burial Diagenesis ◽  
Carbonate Mound ◽  
History Of ◽  
Homogenization Temperatures ◽  
Clumped Isotope

The Hudson Bay sedimentary basin was overlooked geologically until two decades ago. Recent efforts to understand the palaeogeothermal history of this basin have led to the evaluation of fluid inclusion microthermometry, apatite fission track, organic matter reflectance and Rock–Eval analyses. Although apatite fission track and organic maturity indicators tend to show relatively low maximum burial temperatures (60–80°C), evidence of potential oil slicks on the sea surface and oil and gas shows in offshore wells have been reported across Hudson Bay. Fluid inclusion microthermometry in a carbonate mound sequence suggests homogenization temperatures of 118 ± 25 and 93 ± 10°C for recrystallized synsedimentary marine calcite and late pore-filling burial calcite, respectively. This sequence provides an interesting geological framework to test the application of clumped isotope thermometry against independent geothermometers. Here, we present clumped isotope data acquired on the late calcite cements and diagenetically altered early marine phases. The integration of clumped isotopic data with other thermal indicators allows the reconstruction and refinement of the thermal–diagenetic history of these carbonates by confirming an episode of heating, probably of hydrothermal origin and prior to normal burial diagenesis, that reset both fluid inclusions and the clumped isotope indicators without recrystallization.

scholarly journals Oil and gas source and accumulation of Zhongqiu 1 trap in Qiulitage structural belt, Tarim Basin, NW China

2020 ◽  
Vol 47 (3) ◽  
pp. 548-559
Author(s):  
Jian LI ◽  
Jin LI ◽  
Zengye XIE ◽  
Chao WANG ◽  
Haizu ZHANG ◽  
...  
Keyword(s):  
Tarim Basin ◽  
Oil And Gas ◽  
Nw China ◽  
Gas Source
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