Studies on natural gas production prediction and risk quantification of Sinian gas reservoir in Sichuan Basin

AbstractThe Sinian gas reservoir in the Sichuan Basin has the potential for natural gas exploration and development. Production prediction and risk quantification are important in planning of natural gas resources. Ultimate recoverable reserves (URRs) of Sinian gas reservoir are estimated. Hubbert and Gauss models are used to predict the growth trend of production in the gas reservoir. Based on the prediction results, the Monte Carlo simulation is used to calculate the probability of production realization. The evaluation matrix of risk level is established by using indices of production realization probability and dispersion degree for assessing the risk level of natural gas production. The results show that: (1) compared to the Hubbert model, the production prediction results of the Gauss model have higher accuracy. The Sinian gas reservoir will reach peak production of $$\left( {140 - 285} \right) \times 10^{8} {\text{m}}^{3} /{\text{a}}$$ 140 - 285 × 10 8 m 3 / a in 2036 and will have stable production from 2032 to 2040. By the end of the stable production stage, the URR exploitation degree is about 60% and (2) the Monte Carlo method can be used to obtain the production realization probability for each year. The risk level evaluation matrix can be established by taking the probability of realization and the dispersion degree as evaluation indices, which can provide the systematization of the risk levels. The study can help to better understand the guiding significance for the natural gas exploration and development.

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Quantitative study on natural gas production risk of Carboniferous gas reservoir in eastern Sichuan

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01261-8 ◽

2021 ◽

Author(s):

Guo Yu ◽

Haitao Li ◽

Yanru Chen ◽

Linqing Liu ◽

Chenyu Wang ◽

...

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Natural Gas ◽

Gas Production ◽

Probability Method ◽

Gas Reservoir ◽

Production Risk ◽

Probability Interval ◽

Natural Gas Production ◽

Stable Production

AbstractQuantifying natural gas production risk can help guide natural gas exploration and development in Carboniferous gas reservoirs. In this study, the Monte Carlo probability method is used to obtain the probability distribution and growth curve of each production risk factor and production in a Carboniferous gas reservoir in eastern Sichuan. In addition, the fuzzy comprehensive evaluation method is used to conduct the sensitivity analysis of the risk factors, and the natural gas production and realization probability under different risk factors are obtained. The research results show that: (1) the risk factor–production growth curve and probability distribution are calculated by the Monte Carlo probability method. The average annual production under the stable production stage under different realization probabilities is obtained. The maximum probability range of annual production is $$\left( {43.43 - 126.35} \right) \times 10^{8} {\text{m}}^{3} /{\text{year}}$$ 43.43 - 126.35 × 10 8 m 3 / year , and the probability range is 14.59–92.88%. (2) The risk factor sensitivity analysis is significantly affected by the probability interval. In the entire probability interval, the more sensitive risk factors are the average production of the kilometer-deep well (D) and the production rate in the stable production stage (A). During the exploration and development of natural gas, these two risk factors can be adjusted to increase production.

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ABSTRACT: Dynamic 3D/4D Modeling of Natural Gas Reservoir : Resolving the Ciomplexities of the Niger Delta Formation for Effective Gas Production

AAPG Bulletin ◽

10.1306/3fef4ee7-1741-11d7-8645000102c1865d ◽

2002 ◽

Vol 86 ◽

Author(s):

Theophilus Ukpohor1

Keyword(s):

Natural Gas ◽

Niger Delta ◽

Gas Production ◽

Gas Reservoir ◽

Delta Formation

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Research and Application of Segmented Acid Fracturing Technology in Horizontal Wells of Ultra Deep Carbonate Gas Reservoirs in Southwest China

10.2523/iptc-21445-ms ◽

2021 ◽

Author(s):

Yang Wang ◽

Changlin Zhou ◽

Huali Zhang ◽

Tingting He ◽

Xinyuan Tang ◽

...

Keyword(s):

Natural Gas ◽

Southwest China ◽

Horizontal Wells ◽

Gas Production ◽

Reservoir Temperature ◽

Fracturing Fluid ◽

Gas Reservoir ◽

Acid Rock ◽

Acid Fracturing ◽

Temporary Plugging Agent

Abstract The Shuangyu gas reservoir in Southwest China is a fracture ultra deep carbonate gas reservoir. Its reservoir buried depth is more than 7000m, and the reservoir temperature is about 160°C. In the early stage, the vertical well acid fracturing method was used to obtain the natural gas production, but the gas production decreased rapidly after acid fracturing, which is difficult to achieve economic and efficient development. Segmented acid fracturing of horizontal wells is an effective way to greatly increase gas production. However, segmented acid fracturing of horizontal wells in Shuangyu ultra deep carbonate gas reservoir faces the following problems: (1)High reservoir temperature, fast acid rock reaction speed and short length of acid corrosion fracture. (2) The diameter of horizontal well is small (114.3mm), packer and other tools can not be put into the wellbore. In this paper, through laboratory tests, an acid fracturing fluid with temperature resistance of 160 °C and friction resistance of 35% of water is developed. The fracturing fluid has the characteristics of high viscosity and high concentration of hydrogen ions, which can not only fracture the formation, but also carry out effective acid etching on the fracture during the injection process. Through the experiment, the temporary plugging agent which can meet the temperature of 160 °C and the combination of temporary plugging agent can form a sealing layer in the fracture with the width of 4mm, and the maximum sealing pressure can reach 20MPa. The research results have been successfully applied in well y616. After fracturing, the daily output of natural gas in well Y616 is 1 million cubic meters, which is more than three times that of the surrounding vertical wells.

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Establishment and application of prediction model of natural gas reserve and production in Sichuan Basin

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01189-z ◽

2021 ◽

Vol 11 (6) ◽

pp. 2679-2689

Author(s):

Guo Yu ◽

Yizhu Fang ◽

Haitao Li ◽

Chenyu Wang ◽

Dongming Zhang

Keyword(s):

Natural Gas ◽

Sichuan Basin ◽

Weight Coefficient ◽

Scientific Basis ◽

Gas Production ◽

Growth Trend ◽

Recoverable Reserves ◽

Long Time ◽

The Sichuan Basin ◽

Exploration And Development

AbstractResearch on predicting the growth trend of natural gas reserves and production will help provide a scientific basis for natural gas exploration and development. The metabolically improved modified weight coefficient GM(1,n) method is applied to the multi-cycle Hubbert model to predict the trend of new proven natural gas reserves in the Sichuan Basin. The ultimate recoverable reserves (URR) is introduced as a boundary condition in the production-time series to predict the natural gas production growth. The research results show that: (1) The annual newly added proven natural gas reserves of the Sichuan Basin maintain a multi-cycle growth trend, which will reach the peak reserves in 2034, at which time the proven rate of natural gas will reach 36%. (2) Based on the predicted results of proven reserves, the final recoverable reserves of natural gas are estimated to be $$5.25-5.75\times {10}^{12}{m}^{3}$$ 5.25 - 5.75 × 10 12 m 3 . The production in 2035 will reach $$750-810\times {10}^{8}{\mathrm{m}}^{3}/\mathrm{a}$$ 750 - 810 × 10 8 m 3 / a , and production will grow rapidly. The exploration and development of natural gas in the basin will be prospective for a long time.

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Preliminary Numerical Modeling of CO2 Geological Storage in the Huangcaoxia Gas Reservoir in the Eastern Sichuan Basin, China

Geofluids ◽

10.1155/2019/9545723 ◽

2019 ◽

Vol 2019 ◽

pp. 1-23

Author(s):

Hongwu Lei ◽

Qian Zhang ◽

Xiaochun Li

Keyword(s):

Sichuan Basin ◽

Temperature Drop ◽

Injection Pressure ◽

Injection Rate ◽

Gas Production ◽

Injection Well ◽

Gas Reservoir ◽

Gas Field ◽

Eastern Sichuan Basin ◽

Eastern Sichuan

Depleted gas reservoirs are important potential sites for CO2 geological sequestration due to their proven integrity and safety, well-known geological characteristics, and existing infrastructures and wells built for natural gas production. The Sichuan Basin has a large number of gas fields in which approximately 5.89×109 tons of CO2 can be stored. The Huangcaoxia gas field has the best opportunity in the eastern Sichuan Basin for a pilot project of CO2 sequestration due to its relatively large storage capacity and the nearly depleted state. A coupled thermal-hydrodynamic model including faults is built based on the geological and hydrogeological conditions in the Huangcaoxia gas field. The results of the numerical simulations show that the downhole temperature is above 80°C at a downhole pressure of 14 MPa under the constraint of temperature drop in the reservoir due to the strong Joule-Thomson effect. The corresponding injection pressure and temperature at the wellhead are 10.5 MPa and 60°C, respectively. The sizes of the pressure and CO2 plumes after an injection of 10 years are 18 km and 5 km, respectively. The zone affected by temperature change is very small, being about 1-2 km away from the injection well. The injection rate in the injection well Cao 31 averages 6.89 kg/s (21.73×104 tons/a). For a commercial-scale injection, another four wells (Cao 9, Cao 30, Cao 6, and Cao 22) can be combined with the Cao 31 well for injection, approaching an injection rate of 35 kg/s (1.10×106 tons/a). Both the pressure and temperature of CO2 injection decrease with the increasing depleted pressure in the gas reservoir when the latter is below 6 MPa. With the technique of CO2-enhanced gas recovery (CO2-EGR), the CO2 injection rate is improved and approximately 1.58×107 kg of gas can be produced during a studied time period of 10 years.

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4D multi-physical stress modelling during shale gas production: A case study of Sichuan Basin shale gas reservoir, China

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2018.04.036 ◽

2018 ◽

Vol 167 ◽

pp. 929-943 ◽

Cited By ~ 10

Author(s):

Haiyan Zhu ◽

Xuanhe Tang ◽

Qingyou Liu ◽

Kuidong Li ◽

Jialin Xiao ◽

...

Keyword(s):

Shale Gas ◽

Sichuan Basin ◽

Physical Stress ◽

Gas Production ◽

Gas Reservoir ◽

Shale Gas Reservoir

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Investigation of the Enrichment and Accumulation of Normal Pressure Shale Gas in Anchang Syncline Outside of Sichuan Basin

Frontiers in Earth Science ◽

10.3389/feart.2021.802142 ◽

2022 ◽

Vol 9 ◽

Author(s):

Baofeng Lan ◽

Fuping Zhao ◽

Shaopeng Li ◽

Haishen Jiang ◽

Song Liu ◽

...

Keyword(s):

Shale Gas ◽

Sichuan Basin ◽

Normal Pressure ◽

Gas Production ◽

Gas Pressure ◽

Type I ◽

Gas Reservoir ◽

Accumulation Pattern ◽

Preservation Conditions ◽

Exploration And Development

Gas shales from the Wufeng-Longmaxi Formation in Anchang syncline in northern Guizhou area of Sichuan Basin are stable in distribution and can be classified as type I shale gas reservoir with great resource potential. The exploration and development of shale gas in Anchang syncline have achieved great progress. However, the enrichment rule and accumulation pattern of shale gas in Anchang syncline are still not clear at the present. Gas pressure in the Wufeng-Longmaxi Formations shales in Anchang syncline is normal. The maximum tested gas production in the field ranges from 18,000 to 58,000 m3/d. However, gas production of shale wells varies greatly even in the same platform. In order to understand the shale gas enrichment and accumulation and improve the effective development of shale gas in this area, comparative analyses on the geological characteristics and preservation conditions of gas reservoirs in several typical wells were carried out from the perspective of geology, petrophysics, geophysics, and well logging. Results show that shale gas in Anchang syncline has the characteristics of accumulating in both deep central position and gently wings. Tectonic preservation condition is the key factor to high gas production in Anchang area. The hydrological conditions, syncline structure, fault distribution, and cap rock quality comprehensively control the gas pressure and gas bearing capacity of shale reservoir. According to these factors, an accumulation model of shales with normal gas pressure is established: syncline controls the distribution of gas reservoir; fault controls the boundary of the reservoir; preservation conditions controls gas capacity. The results are benefit for the rolling exploration and development of shale gas in Anchang area, and are important for the development of normal pressure shale gas in northern Guizhou area.

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Vug and fracture characterization and gas production prediction by fractals: Carbonate reservoir of the Longwangmiao Formation in the Moxi-Gaoshiti area, Sichuan Basin

Interpretation ◽

10.1190/int-2019-0260.1 ◽

2020 ◽

Vol 8 (3) ◽

pp. SL159-SL171

Author(s):

Chang Li ◽

Liqiang Sima ◽

Guoqiong Che ◽

Wang Liang ◽

Anjiang Shen ◽

...

Keyword(s):

Fractal Dimension ◽

Sichuan Basin ◽

Fractal Dimensions ◽

Gas Production ◽

Carbonate Reservoir ◽

Carbonate Reservoirs ◽

Box Dimension ◽

Longwangmiao Formation ◽

Gas Production Prediction ◽

Production Prediction

A comprehensive knowledge of the development and connectivity of fractures and vugs in carbonate reservoirs plays a key role in reservoir evaluation, ultimately affecting the gas prediction of this kind of heterogeneous reservoir. The carbonate reservoirs with fractures and vugs that are well developed in the Longwangmiao Formation, Sichuan Basin are selected as a research target, with the fractal dimension calculated from the full-bore formation microimager (FMI) image proposed to characterize the fractures and vugs. For this purpose, the multipoint statistics algorithm is first used to reconstruct a high-resolution FMI image of the full borehole wall. And then, the maximum class-variance method (the Otsu method) realizes the automatic threshold segmentation of the FMI image and acquisition of the binary image, which accurately characterizes the fractures and vugs. Finally, the fractal dimension is calculated by the box dimension algorithm, with its small value difference enlarged to obtain a new fractal parameter ([Formula: see text]). The fractal dimensions for four different kinds of reservoirs, including eight subdivided models of vugs and fractures, show that the fractal dimension can characterize the development and the connectivity of fractures and vugs comprehensively. That is, the more developed that the fractures and vugs are, the better the connectivity will be, and simultaneously the smaller that the values of the fractal dimensions are. The fractal dimension is first applied to the gas production prediction by means of constructing a new parameter ([Formula: see text]) defined as a multiple of the effective thickness ([Formula: see text]), porosity (Por), and fractal dimension ([Formula: see text]). The field examples illustrate that the fractal dimensions can effectively characterize the fractures and vugs in the heterogeneous carbonate reservoir and predict its gas production. In summary, the fractals expand the characterization method for the vugs and fractures in carbonate reservoirs and extend its new application in gas production prediction.

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