A Dynamic Workflow of Well Health Issue Prediction – Sulfur Deposition

2021 ◽  
Author(s):  
Bashirul Haq

Abstract Sour gas reservoirs are vital sources for natural gas production. Sulphur deposition in the reservoir reduces a considerable amount of gas production due to permeability reduction. Consequently, well health monitoring and early prediction of Sulphur deposition are crucial for effective gas production from a sour gas reservoir. Dynamic gas material balance analysis is a useful technique in calculating gas initially in place utilizing the flowing wellhead or bottom hole pressures and rates during the well's lifetime. The approach did not apply to monitor a producing gas's health well and detect Sulphur deposition. This work aims to (i) modify dynamic gas material balance equation by adding the Sulphur deposition term, (ii) build a model to predict and validate the issue utilizing the modified equation. A unique form of the flowing material balance is developed by including Sulphur residue term. The curve fitting tool and modified flowing gas material balance are applied to predict well-expected behaviour. The variation between expected and actual performance indicates the health issue of a well. Initial, individual components of the model are tested. Then the model is validated with the known values. The workflow is applied to active gas field and correctly detected the health issue. The novel workflow can accurately predict Sulphur evidence. Besides,the workflow can notify the production engineers to take corrective measures about the subject. Keywords: Sulfur deposition, Dynamic gas material balance analysis, Workflow

2019 ◽  
Author(s):  
Azis Hidayat ◽  
Dwi Hudya Febrianto ◽  
Elisa Wijayanti ◽  
Diniko Nurhajj ◽  
Ahmad Sujai ◽  
...  

1994 ◽  
Author(s):  
S. L. West ◽  
P. J. R. Cochrane

Tight shallow gas reservoirs in the Western Canada Basin present a number of unique challenges in accurately determining reserves. Traditional methods such as decline analysis and material balance are inaccurate due to the formations' low permeabilities and poor pressure data. The low permeabilities cause long transient periods not easily separable from production decline using conventional decline analysis. The result is lower confidence in selecting the appropriate decline characteristics (exponential or harmonic) which significantly impacts recovery factors and remaining reserves. Limited, poor quality pressure data and commingled production from the three producing zones results in non representative pressure data and hence inaccurate material balance analysis. This paper presents the merit of two new methods of reserve evaluation which address the problems described above for tight shallow gas in the Medicine Hat field. The first method applies type curve matching which combines the analytical pressure solutions of the diffusivity equation (transient) with the empirical decline equation. The second method is an extended material balance which incorporates the gas deliverability theory to allow the selection of appropriate p/z derivatives without relying on pressure data. Excellent results were obtained by applying these two methodologies to ten properties which gather gas from 2300 wells. The two independent techniques resulted in similar production forecasts and reserves, confirming their validity. They proved to be valuable, practical tools in overcoming the various challenges of tight shallow gas and in improving the accuracy in gas reserves determination in the Medicine Hat field.


2013 ◽  
Vol 712-715 ◽  
pp. 1096-1099
Author(s):  
Ling Feng Li

For natural gas well in sour gas reservoirs, very serious corrosion in the completed well system is an important factor of gas production system life. In order to ensure the long-term development of gas wells, this paper mainly introduces material corrosion prevention technology in the completed well system, such as corrosion-resistant alloy steel corrosion control technology, bimetallic combination tubing, corrosion inhibitor technology and so on. By taking LJ Gas Field as an example, this paper introduces the material corrosion prevention technology in the completed well system in LJ Gas Field. For application in the completed well system in LJ Gas Field, the technology above have good performance of corrosion resistance.


2012 ◽  
Vol 485 ◽  
pp. 429-432
Author(s):  
Ling Feng Li ◽  
Xiao Ming Liu ◽  
Zhi Qiang Huang

For natural gas well with high content of CO2 and H2S, very serious corrosion in the gas well string is an important factor of gas production system life. In order to ensure the long-term development of gas wells, this paper mainly study the corrosion-resistant material selection of tubing and casing in sour gas reservoirs under coexistence of H2S and CO2 and proposes the optimization idea and technique of tubing and casing material selection. By taking Puguang gas field as an example, this paper optimizes the material selection of production casing for Puguang gas field. By testing, the optimal materials of gas well string in Puguang gas field have good performance of erosion resistance


2013 ◽  
Vol 275-277 ◽  
pp. 456-461
Author(s):  
Lei Zhang ◽  
Lai Bing Zhang ◽  
Bin Quan Jiang ◽  
Huan Liu

The accurate prediction of the dynamic reserves of gas reservoirs is the important research content of the development of dynamic analysis of gas reservoirs. It is of great significance to the stable and safe production and the formulation of scientific and rational development programs of gas reservoirs. The production methods of dynamic reserves of gas reservoirs mainly include material balance method, unit pressure drop of gas production method and elastic two-phase method. To clarify the characteristics of these methods better, in this paper, we took two typeⅠwells of a constant volume gas reservoir as an example, the dynamic reserves of single well controlled were respectively calculated, and the results show that the order of the calculated volume of the dynamic reserves by using different methods is material balance method> unit pressure drop of gas production method >elastic two-phase method. Because the material balance method is a static method, unit pressure drop of gas production method and elastic two-phase method are dynamic methods, therefore, for typeⅠwells of constant volume gas reservoirs, when the gas wells reached the quasi-steady state, the elastic two-phase method is used to calculate the dynamic reserves, and when the gas wells didn’t reach the quasi-steady state, unit pressure drop of gas production method is used to calculate the dynamic reserves. The conclusion has some certain theoretical value for the prediction of dynamic reserves for constant volume gas reservoirs.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Shijun Huang ◽  
Jiaojiao Zhang ◽  
Sidong Fang ◽  
Xifeng Wang

In shale gas reservoirs, the production data analysis method is widely used to invert reservoir and fracture parameter, and productivity prediction. Compared with numerical models and semianalytical models, which have high computational cost, the analytical model is mostly used in the production data analysis method to characterize the complex fracture network formed after fracturing. However, most of the current calculation models ignore the uneven support of fractures, and most of them use a single supported fracture model to describe the flow characteristics, which magnifies the role of supported fracture to a certain extent. Therefore, in this study, firstly, the fractures are divided into supported fractures and unsupported fractures. According to the near-well supported fractures and far-well unsupported fractures, the SRV zone is divided into outer SRV and inner SRV. The four areas are characterized by different seepage models, and the analytical solutions of the models are obtained by Laplace transform and inverse transform. Secondly, the material balance pseudotime is introduced to process the production data under the conditions of variable production and variable pressure. The double logarithmic curves of normalized production rate, rate integration, the derivative of the integration, and material balance pseudotime are established, and the parameters are interpreted by fitting the theoretical curve to the measured data. Then, the accuracy of the method is verified by comparison the parameter interpretation results with well test results, and the influence of parameters such as the half-length and permeability of supported and unsupported fractures on gas production is analyzed. Finally, the proposed method is applied to four field cases in southwest China. This paper mainly establishes an analytical method for parameter interpretation after hydraulic fracturing based on the production data analysis method considering the uneven support of fractures, which is of great significance for understanding the mechanism of fracturing stimulation, optimization of fracturing parameters, and gas production forecast.


2013 ◽  
Vol 690-693 ◽  
pp. 1516-1519
Author(s):  
Ling Feng Li

For natural gas well in sour gas reservoirs, very serious corrosion in the gas well string is an important factor of gas production system life. In order to ensure the long-term development of gas wells, this paper mainly introduces the tubing and casing corrosion in sour gas reservoirs, corrosion-resistant material selection of tubing and casing in sour gas reservoirs and proposes the optimization idea and technique of tubing material selection.. By taking W 63 well as an example, this paper optimizes the material selection of production casing for W 63 well. For application, the optimal materials of gas well string in W 63 well have good performance of corrosion resistance.


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