Characteristics and Accumulation Mechanism of Quasi-Layered Ordovician Carbonate Reservoirs in the Tazhong Area, Tarim Basin

Wang, Zhaoming; Jin, Sheng; Zhu, Guangyou; Han, Jian; Wang, Yu

doi:10.1260/0144-5987.31.4.545

Cited by 26 publications

(7 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a matter of fact, hydrocarbon preservation's lower temperature limit and effective reservoir burial depth's lower limit may vary largely due to different basin properties, or maybe these lower limits refer to a wide depth range (Zhu et al, 2006;Ma et al, 2007), and we can not give a definite answer by now. In addition, mutual complement between burial time and burial depth is crucial as well (Zhu et al, 2012a;2013a), which may exert great influence on the lower depth limit and result in complexity and diversification of deeplayer fluid phases (Zhang et al, 2011c;Yang et al, 2014;Wang et al, 2013;Zhu et al, 2011a;2013b;Chen et al, 2012). Tarim Basin marine deposit combination was developed mainly in the Paleozoic era, and it has undergone polycyclic superimposition and reconstruction, leading to its complicated oil and gas distribution (Yang et al, 2011;Zhu et al, 2013c;2013d).…”

Section: Introductionmentioning

confidence: 99%

Geology and Hydrocarbon Accumulation of the Large Ultra-Deep Rewapu Oilfield in Tarim Basin, China

Zhu

Liu

Zheng

et al. 2015

Energy Exploration & Exploitation

Self Cite

View full text Add to dashboard Cite

Over the past five years, oil and gas exploration to marine facies carbonate rock in China took on a fast-growing tendency, and a lot of large-scale oil and gas fields were discovered in succession. Particularly in the north of Tarim Basin, the large-scale Rewapu oil field was recently discovered in the Ordovician carbonate rock layer system with buried depth of 7,000 meters, manifesting that a significant potential of exploration exists in Tarim Basin's deep layer and ultra deep layer of Tarim basin. The results indicate that reservoirs of Rewapu oilfield are low porosity and low permeability layers karst reservoirs, reservoir temperature is around at 160 ℃ with oil, and the crude oil comes from the upper Ordovician source rock of the Manjaer depression. The hydrocarbon accumulation time is in the Late Permian, and since the Triassic sedimentation, the reservoir is in the continuous process of burying. It belongs to the old oil and gas system. Due to low geothermal gradient and late quick deep burial, oil reservoir has yet to be cracked, so well-preserved old oil reservoir can be discovered at the depth of 7000 m. The Ordovician carbonate reservoir in Rewapu was a fracture-cavity oil reservoir, and the oil and gas distribution and enrichment are controlled not by the local structure, but by the distribution and the development degree of Ordovician carbonate reservoir. The reservoirs of Rewapu block are mainly distributed in the Ordovician Yijianfang formation and at the top Yingshan formation, and the reservoir development degree was controlled by the karstification, the degree of fracture development and the sedimentation facies, concentrating into belts in plane and not controlling by the depth vertically. The overlying strata are limestone of Tumuxiuke formation and marls and limestone of Sangtamu formation in the upper Ordovician. Rewapu oil reservoir features stratified oil and mainly contains normal oil with low viscosity and high wax. Research results show that Ordovician reservoirs in Rewapu block have relatively large depth of burial, but they are still favorable in quality and sit along the path for the oil and gas's northward migration. Therefore, this block has immense resources potential and boasts good exploration and development outlook. In this paper, we study Rewapu block oil reservoir's geological features and hydrocarbon accumulation mechanism, which is of important significance for directing the exploration to oil and gas at the deep layer and ultra deep layer of Tarim Basin.

show abstract

Section: Introductionmentioning

confidence: 99%

Geology and Hydrocarbon Accumulation of the Large Ultra-Deep Rewapu Oilfield in Tarim Basin, China

Zhu

Liu

Zheng

et al. 2015

Energy Exploration & Exploitation

Self Cite

View full text Add to dashboard Cite

show abstract

“…The multiperiod tectonic movements resulted in the uplift and erosion of strata, forming large unconformities and providing conditions for the formation of weathering crust karst reservoirs. For example, the multiperiod tectonic movements in the PLP marine strata in the Tarim, Sichuan, East Siberian, and Permian basins produced large-scale karst reservoirs (Postnikova et al 2002;Dutton et al 2005;Kang 2008;Zhang et al 2007b;Luo et al 2008;Liu et al 2010;Zhao et al 2012b;Wang et al 2013b;Zhou 2013;Du et al 2014;Yang et al 2014). S o u t h a n d C e n t r a l O m a n S a lt B a s in E a s t e r n F l a n k Fig.…”

Section: Large-scale High-quality Reservoirsmentioning

confidence: 99%

Formation and distribution characteristics of Proterozoic–Lower Paleozoic marine giant oil and gas fields worldwide

et al. 2017

View full text Add to dashboard Cite

There are rich oil and gas resources in marine carbonate strata worldwide. Although most of the oil and gas reserves discovered so far are mainly distributed in Mesozoic, Cenozoic, and upper Paleozoic strata, oil and gas exploration in the Proterozoic-Lower Paleozoic (PLP) strata-the oldest marine strata-has been very limited. To more clearly understand the oil and gas formation conditions and distributions in the PLP marine carbonate strata, we analyzed and characterized the petroleum geological conditions, oil and gas reservoir types, and their distributions in thirteen giant oil and gas fields worldwide. This study reveals the main factors controlling their formation and distribution. Our analyses show that the source rocks for these giant oil and gas fields are mainly shale with a great abundance of type I-II organic matter and a high thermal evolution extent. The reservoirs are mainly gas reservoirs, and the reservoir rocks are dominated by dolomite. The reservoir types are mainly karst and reef-shoal bodies with well-developed dissolved pores and cavities, intercrystalline pores, and fractures. These reservoirs are highly heterogeneous. The burial depth of the reservoirs is highly variable and somewhat negatively correlated to the porosity. The cap rocks are mainly thick evaporites and shales, with the thickness of the cap rocks positively correlated to the oil and gas reserves. The development of high-quality evaporite cap rock is highly favorable for oil and gas preservation. We identified four hydrocarbon generation models, and that the major source rocks have undergone a long period of burial and thermal evolution and are characterized by early and long periods of hydrocarbon generation. These giant oil and gas fields have diverse types of reservoirs and are mainly distributed in paleo-uplifts, slope zones, and platform margin reef-shoal bodies. The main factors that control their formation and distribution were identified, enabling the prediction of new favorable areas for oil and gas exploration.

show abstract

“…With oil and gas exploration and development moving into deeper territory within the Earth's crust, the oil and gas industry's focus will increasingly shift from shallow to medium depths (>2,000 m) to even lower depths (>4,000 m; Ma, Cai, & Zhao, ). In the newly discovered oil fields from 2000 to 2014, the main producing formations were deep carbonate, accounting for 58.6%, and these often contained larger recoverable reserves and a higher output (Davies & Smith, ; Rahimpour‐Bonab, Esrafili‐Dizaji, & Tavakoli, ; Z. Wang, Su, Zhu, Han, & Wang, ; J. Zhang, Hu, & Luo, ; Zou et al, ). In particular, these types of carbonate reservoirs are made almost completely of dolomite from the Lower Palaeozoic and Triassic formations (A. Q. Chen et al, ; W. Z. Zhao et al, ).…”

Section: Introductionmentioning

confidence: 99%

Geochemistry characteristics and dolomitization mechanism of the Upper Cambrian dolomite, eastern Ordos Basin, China

Zhang

Chen

et al. 2019

Geological Journal

View full text Add to dashboard Cite

There are widely developed carbonate formations in the lower Palaeozoic, Ordos Basin, China. However, previous studies have paid more attention to the Ordovician formations and largely ignored the Cambrian formations, which also have a larger sediment thickness. Recently, with the continuous discovery of dolomite gas fields in the Ordovician Majiagou formation, more investigations have begun to focus on the deeper dolomite in the Cambrian Sanshanzi Formation (Є3s). This study looks into the origin of the dolomite through a combination of petrology, major–trace elements, and stable isotope and rare earth element (REE) analysis of samples from five outcrops. The results show that the main dolomite types in the study area are dolarenite (Type 1), micrite‐fine crystalline dolomite (Type 2), and medium crystalline dolomite (Type 3). The δ13C values and δ18O values of each dolomite formation are close to those of seawater‐derived dolomite and have slightly higher Na2+ concentrations, suggesting that dolomite formation is closely related to the denser seawater. The REE compositions are characterized by enrichment for light REEs and depletion for heavy REEs, exhibiting an apparent negative Eu anomaly and a slight negative Ce anomaly, indicating that the dolomites of the Є3s may form in a weak‐reduction to the weak‐oxidation environment. The total REE (ΣREE) concentrations of Type 3 dolomites are lower than other types, suggesting that those dolomites may mean that the REEs are lost during the diagenesis. Type 1 dolomite has lower MgO and CaO values and a higher Mn2+ concentration than the other two types of dolomites, indicating that Type 1 dolomite suffered the action of atmospheric fresh water. Type 2 dolomite has lower Mg and Ca values than Type 3 dolomite, suggesting that Type 3 dolomite has a higher dolomitization degree. Further study into the combined palaeogeographical background confirms the dolomitization model of the study area: Type 1 and Type 2 dolomites may have been formed by penecontemporaneous or seepage–reflux dolomitization during early‐stage diagenesis. Subsequently, stratigraphic uplift lead to the Type 1 dolomite suffering the action of atmospheric fresh water, but there was no dorag dolomitization. Type 2 dolomite became the main dolomite type by seepage–reflux dolomitization in this period. Later, Type 2 dolomite was converted into Type 3 dolomite during progressive burial.

show abstract

Characteristics and Accumulation Mechanism of Quasi-Layered Ordovician Carbonate Reservoirs in the Tazhong Area, Tarim Basin

Cited by 26 publications

References 30 publications

Geology and Hydrocarbon Accumulation of the Large Ultra-Deep Rewapu Oilfield in Tarim Basin, China

Geology and Hydrocarbon Accumulation of the Large Ultra-Deep Rewapu Oilfield in Tarim Basin, China

Formation and distribution characteristics of Proterozoic–Lower Paleozoic marine giant oil and gas fields worldwide

Geochemistry characteristics and dolomitization mechanism of the Upper Cambrian dolomite, eastern Ordos Basin, China

Contact Info

Product

Resources

About