Natural fracture distribution and a new method predicting effective fractures in tight oil reservoirs in Ordos Basin, NW China

Fan, Jun; Qu, Xuefeng; Wang, Chong; Lei, Qihong; Cheng, Liangbing; Yang, Ziqing

doi:10.1016/s1876-3804(16)30096-9

Cited by 43 publications

(9 citation statements)

References 7 publications

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“…The highly scattered distribution of the lenticular reservoir determines the production characteristics of the gas reservoirs: due to the small scale of the effective sand body, the single well production is low, the stable production capacity is poor, and the single well control reserves and the final accumulated yield are low. Generally, the dynamic reservoir controlled by a single well is less than 30 million cubic meters, and the gas production rate can keep 10,000 cubic meters for three years, then the production rate will keep decline for about 7–10 years until the reservoir pressure is too low to produce (Fan et al., 2016; Jang et al., 2016; Zhao et al., 2016).…”

Section: Basic Geological Characteristics Of the Tight Gas Reservoir mentioning

confidence: 99%

Modeling and analyzing gas supply characteristics and development mode in sweet spots of Sulige tight gas reservoir, Ordos Basin, China

Zhang

et al. 2018

Energy Exploration & Exploitation

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In order to study the characteristics of the gas supply and development mode in sweet spots of Sulige tight gas reservoir in Ordos Basin, China, a mathematical model was developed for the typical lenticular reservoirs in tight gas reservoirs, and its analytical solution was obtained. The ideal model was calculated by using the analytical solution. Analysis of the production data indicated a clear boundary between the high-and low-permeability regions of the lenticular reservoir, and the boundary will supply gas to the low-permeability region. The reliability of this finding was validated by real production data. The development mode of the lenticular reservoir was obtained, that is the high-permeability area was first used during the initial production; when the pressure wave reached the boundary in the high-permeability region, the production showed a pseudo-steady state; further increase of the production pressure exceeding the threshold of the surrounding low-permeability region triggered the utilization of the low-porosity and low-permeability regions. The established model can provide useful guidance for the development of similar tight gas reservoirs.

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Section: Basic Geological Characteristics Of the Tight Gas Reservoir mentioning

confidence: 99%

Modeling and analyzing gas supply characteristics and development mode in sweet spots of Sulige tight gas reservoir, Ordos Basin, China

Zhang

et al. 2018

Energy Exploration & Exploitation

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“…Previous studies in this area were primarily concerned with the oil groups from Chang 8 to Chang 6. A lack of systematic investigations of the characteristics, formation, and controlling factors in Chang 2 significantly restrained the target evaluation and optimization analysis [6,7].…”

Section: Introductionmentioning

confidence: 99%

Microscale Mineral and Pore Structure Characterization of the Low-Permeability Sandstone in the Ordos Basin, China

Gao¹,

Sun

Liu

et al. 2021

Advances in Civil Engineering

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Given the insufficient understanding of the characteristics and controlling factors of the low-permeability sandstone reservoir in the Heshui area, the Ordos Basin, the present study examined the microscale mineral and pore structure of Chang 2 reservoir. It analyzed its major controlling factors using a series of methods, including imaging and indirect methods. The results show that the rocks of Chang 2 reservoir in the study area are dominated by lithic arkose and feldspathic detritus quartz sandstone. The reservoir space develops intragranular pores, feldspar dissolved pores, lithic dissolved pores, and intercrystallite pores. Microcracks can occasionally be found. The average porosity is 10.5%, and the average permeability is 2.2 mD, featuring a low-porosity-ultralow-permeability reservoir. During the reservoir development, traps formed by small-scale nose-shaped uplifts resulting from the tectonic effects provide opportunities for good reservoir space. Sedimentation and diagenetic processes control the degree of development and direction of the evolution of reservoir porosity to a certain degree. Multisegment capillary pressure curve and long missing zone were corresponding to relatively good pore-throat structures. Illite was the predominant diagenetic clay minerals that determine the reservoir quality. These three effects all contribute to the overall development of the reservoir.

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“…Natural fracturing of carbonates depends on multiple factors related to both diagenetic processes and phases of structural deformation (Laubach et al, 2009;Frost and Kerans, 2010;Lamarche et al, 2012;Fan et al, 2016). Carbonate sediments affected by early diagenesis may experience significant changes in their elastic and brittle behaviour (Di Naccio et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Reservoir Properties of Barremian–aptian Urgonian Limestones, Se France, Part 2: Influence of Diagenesis and Fracturing

Cochard

Léonide

Borgomano

et al. 2020

Journal of Petroleum Geology

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Integrated sedimentological, diagenetic and structural analyses have been carried out on microporous and tight Urgonian (Barremian – Aptian) limestones in a study area in SE France in order to understand the influence of diagenetic changes and structural deformation on the spatial distribution of reservoir properties. A diagenetic history for the carbonates was established and was divided into phases which correspond to episodes of regional geodynamic activity. Petrographic (optical, SEM and cathodoluminescence microscopy), structural and geochemical (δ18O, δ13C) studies were carried out to characterize the cement phases in the carbonates, especially micrite and blocky calcite, and to investigate their relationship with episodes of fracturing. Eleven calcite cement phases and four micritic cement phases were identified in relation to the two main phases of structural deformation which affected the Urgonian limestones. A first phase of micrite cementation occurred early in the diagenetic history and was linked to early marine cementation at the tops and bases of depositional cycles during the Barremian. A major phase of micrite recrystallization, which generated microporosity in carbonates that had previously been preserved from early cementation, was followed by a first phase of blocky calcite which occluded intergranular pore spaces. The blocky cement formed in a shallow burial meteoric environment and contributed to the preservation of microporosity during late Durancian tectonism (Albian – Cenomanian). A second phase of blocky calcite is associated with fracture activation during latest Eocene (Priabonian) – Oligo‐Miocene extension. Reservoir rock‐types (RRTs) proposed in a previous study were consistent with the diagenetic characteristics and the results of δ13C / δ18O analyses. Microporous RRTs formed as a result of early to late shallow burial processes and display low δ13C values; whereas cemented RRTs developed both due to early marine cementation (with high δ13C values) and/or as a result of cementation related to fluid flow linked to the reactivation of faults and fractures. This suggests that some late diagenetic and microstructural processes were pre‐determined by early diagenetic changes in the carbonates. The resulting stratigraphic architecture consists of a vertical stacking of weakly fractured microporous limestone intervals alternating with highly fractured, cemented limestone units.

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Natural fracture distribution and a new method predicting effective fractures in tight oil reservoirs in Ordos Basin, NW China

Cited by 43 publications

References 7 publications

Modeling and analyzing gas supply characteristics and development mode in sweet spots of Sulige tight gas reservoir, Ordos Basin, China

Modeling and analyzing gas supply characteristics and development mode in sweet spots of Sulige tight gas reservoir, Ordos Basin, China

Microscale Mineral and Pore Structure Characterization of the Low-Permeability Sandstone in the Ordos Basin, China

Reservoir Properties of Barremian–aptian Urgonian Limestones, Se France, Part 2: Influence of Diagenesis and Fracturing

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