Improved reservoir characterization by employing hydraulic flow unit classification in one of Iranian carbonate reservoirs

Rafiei, Yousef; Motie, Mohadeseh

doi:10.26804/ager.2019.03.06

Cited by 12 publications

(8 citation statements)

References 20 publications

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“…Lithologies control the reservoir physical properties. Compaction, cementation, dissolution, and recrystallization during the later diagenetic stage led to the development of a multimodal pore structure with weak pore connectivity, poor pore configuration and physical properties, and argillaceous fillers in the pores and pore throats (Lai et al, 2013;Rong et al, 2014;Pan et al, 2019;Rafiei et al, 2019).…”

Section: Geological Settingmentioning

confidence: 99%

Pore Structure Characterization of Clay Minerals in the Lower Karamay Formation Conglomerate Reservoir in the Junggar Basin and its Impact on Hydrocarbon Storage and Seepage

Abitkazy

et al. 2021

Acta Geologica Sinica (Eng)

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The micro-nano pore structure of conglomerate in the Lower Karamay Formation of the Xinjiang Oilfield, Junggar Basin, northern China is characterized to predict its impact on fluid reserves and seepage. Authigenic clay minerals are mainly kaolinite (67%), followed by an illite/smectite mixed layer (18%), illite (10%), and chlorite (5%). For kaolinite, pore throats between 0-200 nm are dominant, accounting for 90% of the total pore throats. For illite/smectite mixed layer, pore throats also between 0-200 nm account for nearly 80%, while pore throats between 200-500 nm only account for 15%. For illite, pore throats below 100 nm account for about 80%, while pore throats in the range of 100-500 nm only account for 20%. For chlorite, most throats are below 200 nm. The pore roundness of illite is the highest, while the pore roundness of chlorite is relatively lower. The lower limits of the dynamic and static pore throat radii are 42.128 nm and 72.42 nm, respectively. The theoretical contribution rates of the illite/smectite mixed layer, kaolinite, illite and chlorite to storage/ seepage are 60%/45.86%, 52.72%/38.18%, 37.07%/28.78% and 32.97%/26.3%, respectively. Therefore, the contribution rates of clay minerals in the study area are as follows: illite/smectite mixed layer, kaolinite, illite and chlorite.

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Section: Geological Settingmentioning

confidence: 99%

Pore Structure Characterization of Clay Minerals in the Lower Karamay Formation Conglomerate Reservoir in the Junggar Basin and its Impact on Hydrocarbon Storage and Seepage

Abitkazy

et al. 2021

Acta Geologica Sinica (Eng)

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“…Interpretation model for the results of well test in fault-karst reservoirs is more complicated [34][35][36][37] when compared to that in conventional reservoirs. Commonly, the log-log diagnostic testing curves are used for the recognition of the number of reservoir bodies, calculation of the equivalent porosity and permeability, and speculation of the production behavior of fault-karst reservoirs (Figure 8).…”

Section: Internal Structure Characterization Using Well Testmentioning

confidence: 99%

New Method for Characterizing Internal Structure of Fault-Karst Reservoirs and Analysis on Acidizing Fracturing Effect: A Case Study in HLHT Oilfield, Tarim Basin, NW China

et al. 2021

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Superimposed tectonic movement and karst erosion resulted in a combination of fractures and irregular caves in deep/ultradeep carbonate rocks, typically along major fault swarms. Outlining these fault-karst reservoirs mainly depends on recognizing the strong reflection in seismic profiles; however, characterizing their internal structures is still difficult, which are represented as weak amplitude in seismic profiles. This study intended to propose a method to dissect the internal structure of fault-karst reservoirs, which contains four steps: (1) elimination of the signal interference by the covering bed with strong energy and recognition of internal reservoirs with low energy based on seismic data conversion, frequency division, and inversion; (2) gradient structure tensor analysis based on an anisotropic Gaussian filter for fault-karst reservoir outlining; (3) internal faults and cave recognition on the basis of wave-based inversion; and (4) reevaluation of the number and scale of these faults and caves based on seismic recognition and well test results and verification of their volumes and hydrocarbon reserves. The method was used in the evaluation of the fault-karst reservoir in the Halahatang (HLHT) oilfield, which is located in the north of Tarim Basin. The results show that the fault-karst reservoirs along major faults and their internal structures are effectively recognized, and the error of the predicted depth of the reservoirs decreases from more than 20 m before to less than 4 m now; the drilling success ratio increases from 70% to 90%. In addition, the method supports the recognition of untapped fault-karst reservoirs around shut-in wells, which provides guidance for sidetracking plans. Further, by comparing the geophysical volume of fault-karst reservoirs and the reserve predicted by production performance, the untapped reserve in a certain reservoir can be evaluated; on this basis, producing wells received high yields by targeted acid fracturing. In summary, the method effectively improves the prediction accuracy and the recovery efficiency of fault-karst reservoirs.

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“…Brittleness is a physical attribute of coal mass, which is related to the mineral composition and stress action of coal mass [46][47][48]. Reservoir rock brittleness is mechanical properties evaluation, borehole wall stability evaluation, and the important indexes for evaluation of hydraulic fracturing effect.…”

Section: Study On Brittleness Index Of Coal Massmentioning

confidence: 99%

Study on Mechanical Behavior and Seepage Characteristics of Coal Mass during Unloading

2021

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With the increase of buried depth, the content of gas increases gradually. The gas in the mining process will lead to gas gush and other dynamic disasters, or even coal and gas gushing in front of the working face. Therefore, the study on the permeability distribution of coal and the surrounding rock is the core work of coal and gas mining at the same time. To study the mechanical behaviors and seepage characteristics of coal mass during unloading is to prepare for coal and gas mining in the future, which can not only ensure the safety of operators to the maximum extent but also increase the mining rate as much as possible. Based on the stress-strain curve and seepage curve, the brittleness index and seepage characteristics of coal are analyzed. The greater the brittleness index is, the more likely the coal mass is to produce cracks, and then to form large cracks, or even fracture. Through the study of brittleness index and seepage characteristics of coal mass, the mechanical behavior of coal mass can be easily obtained, so as to guide the mining of coal mass.

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Improved reservoir characterization by employing hydraulic flow unit classification in one of Iranian carbonate reservoirs

Cited by 12 publications

References 20 publications

Pore Structure Characterization of Clay Minerals in the Lower Karamay Formation Conglomerate Reservoir in the Junggar Basin and its Impact on Hydrocarbon Storage and Seepage

Pore Structure Characterization of Clay Minerals in the Lower Karamay Formation Conglomerate Reservoir in the Junggar Basin and its Impact on Hydrocarbon Storage and Seepage

New Method for Characterizing Internal Structure of Fault-Karst Reservoirs and Analysis on Acidizing Fracturing Effect: A Case Study in HLHT Oilfield, Tarim Basin, NW China

Study on Mechanical Behavior and Seepage Characteristics of Coal Mass during Unloading

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