MICROSTRUCTURE FORMED BY FAULT DEFORMATION AND ITS INFLUENCES ON OIL AND GAS FILLING IN THE LUNNAN UPLIFT, TARIM BASIN

2019 ◽  
Author(s):  
Wenyuan Yan ◽  
◽  
Ming Zha
Keyword(s):  
Tarim Basin ◽  
Oil And Gas ◽  
Fault Deformation

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 Fluid geochemistry of the Jurassic Ahe Formation and implications for reservoir formation in the Dibei area, Tarim Basin, northwest China

2018 ◽  
Vol 36 (4) ◽  
pp. 801-819 ◽  
Author(s):  
Shuangfeng Zhao ◽  
Wen Chen ◽  
Zhenhong Wang ◽  
Ting Li ◽  
Hongxing Wei ◽  
...  
Keyword(s):  
Natural Gas ◽  
Tarim Basin ◽  
Oil And Gas ◽  
Northwest China ◽  
Source Rocks ◽  
Coal Measure ◽  
Hydrocarbon Generation ◽  
Gas Reservoirs ◽  
Isotopic Analyses ◽  
Jurassic Coal

The condensate gas reservoirs of the Jurassic Ahe Formation in the Dibei area of the Tarim Basin, northwest China are typical tight sandstone gas reservoirs and contain abundant resources. However, the hydrocarbon sources and reservoir accumulation mechanism remain debated. Here the distribution and geochemistry of fluids in the Ahe gas reservoirs are used to investigate the formation of the hydrocarbon reservoirs, including the history of hydrocarbon generation, trap development, and reservoir evolution. Carbon isotopic analyses show that the oil and natural gas of the Ahe Formation originated from different sources. The natural gas was derived from Jurassic coal measure source rocks, whereas the oil has mixed sources of Lower Triassic lacustrine source rocks and minor amounts of coal-derived oil from Jurassic coal measure source rocks. The geochemistry of light hydrocarbon components and n-alkanes shows that the early accumulated oil was later altered by infilling gas due to gas washing. Consequently, n-alkanes in the oil are scarce, whereas naphthenic and aromatic hydrocarbons with the same carbon numbers are relatively abundant. The fluids in the Ahe Formation gas reservoirs have an unusual distribution, where oil is distributed above gas and water is locally produced from the middle of some gas reservoirs. The geochemical characteristics of the fluids show that this anomalous distribution was closely related to the dynamic accumulation of oil and gas. The period of reservoir densification occurred between the two stages of oil and gas accumulation, which led to the early accumulated oil and part of the residual formation water being trapped in the tight reservoir. After later gas filling into the reservoir, the fluids could not undergo gravity differentiation, which accounts for the anomalous distribution of fluids in the Ahe Formation.

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.

Hydrocarbon-bearing characteristics of the SB1 strike-slip fault zone in the north of the Shuntuo Low Uplift, Tarim Basin

2020 ◽  
Vol 27 (1) ◽  
pp. petgeo2019-144
Author(s):  
Ziyi Wang ◽  
Zhiqian Gao ◽  
Tailiang Fan ◽  
Hehang Zhang ◽  
Lixin Qi ◽  
...  
Keyword(s):  
Fault Zone ◽  
Tarim Basin ◽  
Oil And Gas ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Hydrocarbon Exploration ◽  
Phase Iii ◽  
Permeability Barrier ◽  
The North ◽  
Migration Pathways

The SB1 strike-slip fault zone, which developed in the north of the Shuntuo Low Uplift of the Tarim Basin, plays an essential role in reservoir formation and hydrocarbon accumulation in deep Ordovician carbonate rocks. In this research, through the analysis of high-quality 3D seismic volumes, outcrop, drilling and production data, the hydrocarbon-bearing characteristics of the SB1 fault are systematically studied. The SB1 fault developed sequentially in the Paleozoic and formed as a result of a three-fold evolution: Middle Caledonian (phase III), Late Caledonian–Early Hercynian and Middle–Late Hercynian. Multiple fault activities are beneficial to reservoir development and hydrocarbon filling. In the Middle–Lower Ordovician carbonate strata, linear shear structures without deformation segments, pull-apart structure segments and push-up structure segments alternately developed along the SB1 fault. Pull-apart structure segments are the most favourable areas for oil and gas accumulation. The tight fault core in the centre of the strike-slip fault zone is typically a low-permeability barrier, whilst the damage zones on both sides of the fault core are migration pathways and accumulation traps for hydrocarbons, leading to heterogeneity in the reservoirs controlled by the SB1 fault. This study provides a reference for hydrocarbon exploration and development of similar deep-marine carbonate reservoirs controlled by strike-slip faults in the Tarim Basin and similar ancient hydrocarbon-rich basins.

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

Geological origins of seismic bright spot reflections in the Ordovician strata in the Halahatang area of the Tarim Basin, western China

2018 ◽  
Vol 55 (12) ◽  
pp. 1297-1311 ◽  
Author(s):  
Wei Yang ◽  
Xiaoxing Gong ◽  
Wenjie Li
Keyword(s):  
Tarim Basin ◽  
Oil And Gas ◽  
High Amplitude ◽  
Hydrothermal Activity ◽  
Hydrocarbon Exploration ◽  
Western China ◽  
Bright Spot ◽  
Gas Reservoirs ◽  
Seismic Section ◽  
Bright Spots

Anomalously high-amplitude seismic reflections are commonly observed in deeply buried Ordovician carbonate strata in the Halahatang area of the northern Tarim Basin. These bright spots have been demonstrated to be generally related to effective oil and gas reservoirs. These bright spot reflections have complex geological origins, because they are deeply buried and have been altered by multi-phase tectonic movement and karstification. Currently, there is no effective geological model for these bright spots to guide hydrocarbon exploration and development. Using core, well logs, and seismic data, the geological origins of bright spot are classified into three types, controlled by karstification, faulting, and volcanic hydrothermal activity. Bright spots differing by geological origin exhibit large differences in seismic reflection character, such as reflection amplitude, curvature, degree of distortion, and the number of vertically stacked bright spots in the seismic section. By categorizing the bright spots and the seismic character of the surrounding strata, their geological origins can after be inferred. Reservoirs formed by early karstification were later altered by epigenetic karstification. Two periods of paleodrainage further altered the early dissolution pores. In addition, faults formed by tectonic uplift also enhanced the dissolution of the flowing karst waters. Some reservoirs were subsequently altered by Permian volcanic hydrothermal fluids.

Major Controls on the Evolution of the Cambrian Dolomite Reservoirs in the Keping Area, Tarim Basin

2013 ◽  
Vol 734-737 ◽  
pp. 377-383
Author(s):  
Qing Li ◽  
Xue Lian You ◽  
Wen Xuan Hu ◽  
Jing Quan Zhu ◽  
Zai Xing Jiang
Keyword(s):  
Tarim Basin ◽  
Significant Contribution ◽  
Oil And Gas ◽  
Geochemical Data ◽  
Acid Dissolution ◽  
High Quality ◽  
Secondary Porosity ◽  
Oil And Gas Exploration ◽  
Reservoir Evolution ◽  
Major Factors

The Cambrian dolomite reservoir is an important target in oil and gas exploration. The Penglaiba section in the Keping area is typically examined in studies dealing with the Cambrian dolomite reservoirs of northwestern Tarim Basin. Based on sedimentological, petrographic, and geochemical data, lithofacies and fluids are identified as the major factors that control the dolomite reservoir in the study area. Lithoacies are fundamental to reservoir evolution because they provide suitable channels for dolomitization and dissolution of fluids that, in turn, facilitate the formation of high quality reservoirs. The lithofacies which could form high-quality reservoirs in the study area are: slope slip (collapse) facies, gypsum related facies, and algae dolomite facies. The sources of fluids include seawater, meteoric freshwater, diagenetic/hydrocarbon fluid, and hydrothermal fluid. These fluids lead to dolomitization, penecontemporaneous meteoric dissolution, hypergene dissolution, organic acid dissolution and hydrothermal dissolution that result in secondary porosity, and as such, they have a significant contribution to reservoir evolution.

Sign in / Sign up

Export Citation Format

Share Document