Feasibility Analysis of Gas Storage in JB Area Caprock Evaluation

2011 ◽  
Vol 110-116 ◽  
pp. 3117-3124
Author(s):  
Lei Shi ◽  
Shu Sheng Gao

Underground gas storages (UGS) are widely used to store the excess of produced natural gas during periods of low demand, and relieve the pressure during periods of high demand. Depleted natural gas reservoir is generally the best choice against others. Proper selection of a depleted gas reservoir is essential to the succession, steady and reliability of UGS in the long run. Sealing capacity of caprock is an important index for measuring the performance of gas storage reservoir. In order to analysis feasibility of UGS in JB area, the development characteristics of caprock were studied, the sealing gas effectiveness of caprock was evaluated. it was concluded that the main caprock was the formation of evaporative carbonate platform, and the breakthrough pressure of cap rock was high. The cap rocks with good sealing capacity were distributed in the area between S224 well and S39 well. The sealing ability was comprehensively evaluated by use of the development features and sealing capacity of caprock.

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 576 ◽  
Author(s):  
Cheng Cao ◽  
Jianxing Liao ◽  
Zhengmeng Hou ◽  
Hongcheng Xu ◽  
Faisal Mehmood ◽  
...  

Underground gas storage reservoirs (UGSRs) are used to keep the natural gas supply smooth. Native natural gas is commonly used as cushion gas to maintain the reservoir pressure and cannot be extracted in the depleted gas reservoir transformed UGSR, which leads to wasting huge amounts of this natural energy resource. CO2 is an alternative gas to avoid this particular issue. However, the mixing of CO2 and CH4 in the UGSR challenges the application of CO2 as cushion gas. In this work, the Donghae gas reservoir is used to investigate the suitability of using CO2 as cushion gas in depleted gas reservoir transformed UGSR. The impact of the geological and engineering parameters, including the CO2 fraction for cushion gas, reservoir temperature, reservoir permeability, residual water and production rate, on the reservoir pressure, gas mixing behavior, and CO2 production are analyzed detailly based on the 15 years cyclic gas injection and production. The results showed that the maximum accepted CO2 concentration for cushion gas is 9% under the condition of production and injection for 120 d and 180 d in a production cycle at a rate of 4.05 kg/s and 2.7 kg/s, respectively. The typical curve of the mixing zone thickness can be divided into four stages, which include the increasing stage, the smooth stage, the suddenly increasing stage, and the periodic change stage. In the periodic change stage, the mixed zone increases with the increasing of CO2 fraction, temperature, production rate, and the decreasing of permeability and water saturation. The CO2 fraction in cushion gas, reservoir permeability, and production rate have a significant effect on the breakthrough of CO2 in the production well, while the effect of water saturation and temperature is limited.


Author(s):  
Hamidreza Kakhsaz ◽  
Abdolhamid Ansari

Underground storage of natural gas is an inevitable necessity because of increasing growth of household energy consumption, the high share of natural gas in the energy basket, high costs of development of production resources, and refining. Considering the growth of demand and variation of natural gas consumption as a massive and inexpensive energy carrier, also unbalanced supply and demand for natural gas in cold seasons, there is a need for natural gas storage for preventing lack of gas during peak gas consumption. In this way, extra gas is injected into the underground reservoir during storage in summer and taken from that reservoir in the cold seasons. The creation of underground reservoirs for storing natural gas is scheduled to be implemented by the gas storage company and the vulnerability of the transmission and distribution system will be prevented by storing surplus gas in summer for reprocing in winter.


2021 ◽  
Author(s):  
Lina Song ◽  
Hongcheng Xu ◽  
Qiqi Wanyan ◽  
Wei Liao ◽  
Shijie Zhang ◽  
...  

Abstract Inventory verification is one of vital tasks in underground gas storage (UGS) management process. For one reason, it is possible to know exactly how much natural gas is actually in the gas storage and ensure that it can be produced and supplied to the market in winter season when needed. For another, possible natural gas leakage can be discovered in time by inventory verification, to ensure the safe and economic operation of the gas storage. HTB UGS is a gas storage facility rebuilt from a depleted gas reservoir in China, which has been commissioning in June 2013. After 7 years injection-withdrawal cycles, we calculated and analyzed the inventory of this gas storage. First and foremost, we analyzed the data of 13 observation wells, including monitoring of gas-water interface, caprocks, and faults of the HTB UGS. In addition, we carried out core experiments in the laboratory to simulate the multi-cycle injection and withdrawal of gas storage, and analyzed the microscopic pore seepage characteristics of the reservoir during the UGS operation. Next, based on the operating pressure test data of the gas storage, we corrected the formation pressure and calculated the effective inventory. Furthermore, combined with the simulation results that we have carried out in the previous period, the effective inventory of HTB UGS was comprehensively evaluated. The result shows that: 1) The complete monitoring system indicates that the HTB UGS has no gas escaping from the storage field through faults, caprocks or wellbore. 2) The experimental result shows that in the process of gas withdrawal, various forms of natural gas such as jams and bypasses in some areas of the reservoir cannot participate in the flow, leading to this part of natural gas cannot be used. 3) Inventory calculation shows that as of the end of gas withdrawal in March 2020, the book inventory of HTB UGS is 99.8×108m3,while the effective inventory is 91.8×108m3 and the working gas is 39.9×108m3. 4) By acidification or other measures to improve the geological conditions, intensifying the well pattern and extending the gas production time, HTB UGS can increase its effective inventory. With the great efforts in constructing underground gas storage in China and the market-oriented operation of UGS, inventory verification of gas storage will become increasingly important. The inventory analysis method established in this article can provide a certain reference.


2021 ◽  
Author(s):  
Hongbo Huo ◽  
Jinman Li ◽  
Zhong Li ◽  
Xiaocheng Zhang ◽  
Shiming He ◽  
...  

Abstract Objectives/Scope Compared with the underground nature gas storage (UNGS) onshore, the offshore UNGS is further from residential areas and industrial areas, which can shave the peak of natural gas more safely. However, the investment of offshore engineering is higher. Offshore UNGS with reusing offshore depleted gas reservoir construction can not only solves the problems of offshore engineering structure and wells abandonment but also greatly reduces the investment. Methods, Procedures, Process According to the experience of UNGS onshore, the following factors were considered: reservoir buried depth, working gas volume, distance from land, etc. Based on one depleted gasfield in Bohai Bay, the feasibility analysis of an UNGS was carried out, the impact of the offshore UNGS on the environment, the sealing of the underground gas trap and the integrity of the wellbore were evaluated, and the result proves that the sealing of the underground gas trap of the gas field was good. The natural gas pipeline network subsea can provide transportation for the UNGS and compatible to be transformed into the offshore UNGS. However, for one thing, the poor wellbore integrity conditions and imperfect well pattern constraint the reusing, for another, the capacity of offshore facilities need to be improved. Results, Observations, Conclusions According to the economic evaluation, the investment of offshore depleted gas reservoir reusing as UNGS can be reduced by 56% compared with the construction of a new onshore UNGS, and 32% compared with the offshore gas field abandon. A new idea is provided for peak shaving of natural gas, greatly reducing the investment in gas storage construction. Experience has been accumulated by the feasibility analysis of offshore depleted gas field UNGS and that has a bright future. Novel/Additive Information The limitation of natural conditions on project construction, contingency plans for force majeure such as sea ice, storm and earthquake, etc are necessary to be considered, and its implementation still needs the support of the government and relevant non-governmental organizations


1981 ◽  
Vol 21 (02) ◽  
pp. 151-159 ◽  
Author(s):  
G.L. Chierici ◽  
G.A. Gottardi ◽  
R.P. Guidorzi

Abstract The classical approach to forecasting hydrocarbon reservoir behavior is through modeling. Traditional models are based on equations describing the physical behavior of the reservoir-plus-aquifer system; usually the parameters describing aquifer behavior are not known beforehand and are evaluated by a trial-and-error procedure based on the best fit of past reservoir performance. This approach leads to models that are intrinsically realistic, as they reflect the physical nature of the phenomena involved. A completely different approach, based on system theory techniques, is presented in this paper. This technique, called identification, consists of the determination of a mathematical model equivalent to the process under test, the word "equivalent" meaning that the process and the model show the same input/output behavior. As a consequence, an identified model of this type can be used to predict the response of an actual reservoir-plus-aquifer system to different inputs - i.e., to different production schedules. Case histories of the application of the identification technique to actual gas storage reservoirs are presented. Introduction As with many other aspects of the world, a gas reservoir can be considered a dynamical system interacting with an external environment by means of inputs and outputs. The exchanges between a reservoir and the rest of the world occur through wells and the measurable attributes at every well are given by the gas production rate and pressure. Thus, it is possible to consider the cumulative gas production of wells as inputs and the well pressures as outputs of this system. Note that when a water drive mechanism is present, the cumulative quantity of water which has entered the reservoir should be considered one of the system's inputs; however, this information is not usually available since wells are drilled where hydrocarbons, rather than water, are expected. In the selection of a suitable model for a reservoir, the choice between linear and nonlinear models must be made. In many cases, linear models are used because of their relative simplicity and of the general theory that has been developed for their treatment. No general theory can be found for nonlinear systems; this explains why clearly nonlinear systems have been studied, designed, built, tested, and operated using only the linear system theory. A gas reservoir, particularly when used for storage purposes, is virtually a linear system; therefore a model of this type is useful to describe its behavior accurately. Another choice regards the time invariance of the model. Gas reservoirs are time invariant; however, if an aquifer is present and no measurements of the cumulative amount of water which has entered the reservoir are available as a system input, the reservoir behavior will change with time and only a time-dependent model could be completely accurate. The selection of a time-invariant model can lead to a lack of accuracy, particularly for water-driven reservoirs when the first production years are considered; the aquifer contribution to time dependency becomes less important in subsequent years. This paper shows that the limits on the use of time-invariant models are no longer valid for reservoirs subjected to injection/production schedules and that models of this kind can be obtained inexpensively and accurately by means of identification procedures performed on the available system history. SPEJ P. 151^


2018 ◽  
Vol 44 ◽  
pp. 00038 ◽  
Author(s):  
Maciej Dziewiecki

This paper present the idea of a natural gas reservoir, which uses technology of gas storage by adsorption on activated carbon. Such reservoir can be feeded with Liquid Natural Gas. The framework of article includes theoretical principals of gas-solid physical adsorption, and explains most important concepts associated with it. Moreover, concept of such tank and working regime is presented. Selected subject is very promising in the field of natural gas storage, although this is still a niche issue. Lack of universal models of gases physical adsorption made it very difficult to predict the runs of processes occurring in the proposed reservoir, which is why this project was based on models confirmed during in the earlier studies.


Sign in / Sign up

Export Citation Format

Share Document