A New Model to Simulate Gas Injection in Gas Chamber Pumps

2004 ◽  
Vol 126 (4) ◽  
pp. 279-284 ◽  
Author(s):  
S. Pilo-Restuccia ◽  
L. Rojas-Solo´rzano

Currently, there exist large heavy-oil reserves in countries like Venezuela and Canada. In Venezuela, heavy oil represents 69% of the reserves, and its exploitation is not always feasible using traditional pumping technologies. In particular, this is the case of some in-lake oil wells in Venezuela, which are impossible to exploit by means of any known efficient way of oil lifting. An alternative is the gas-chamber pumping (GCP), an intermittent artificial lift method used in diverse areas of USA, in shallow wells with heavy oil and in areas where a source of high-pressure gas exists. Few works are reported on the modeling of the phenomena associated to GCP, the most rigorous being the one published by PDVSA-Intevep in the year 2000. This model, however, omits some key aspects related with gas injection, which affects its precision to simulate or design GCP systems. The present work develops a model to rigorously simulate the stage of gas injection into the chamber, incorporating aspects like the flow of gas from the supply manifold up to the wellhead, the gas expansion within the injection valve, the descending flow along a coiled tubing, and the heat transfer associated. The pressurization process and chamber venting are also modeled. The model predictions are in excellent agreement with experimental data [1].

2021 ◽  
pp. 1-13
Author(s):  
Wang Xiaoyan ◽  
Zhao Jian ◽  
Yin Qingguo ◽  
Cao Bao ◽  
Zhang Yang ◽  
...  

Summary Achieving effective results using conventional thermal recovery technology is challenging in the deep undisturbed reservoir with extra-heavy oil in the LKQ oil field. Therefore, in this study, a novel approach based on in-situ combustion huff-and-puff technology is proposed. Through physical and numerical simulations of the reservoir, the oil recovery mechanism and key injection and production parameters of early-stage ultraheavy oil were investigated, and a series of key engineering supporting technologies were developed that were confirmed to be feasible via a pilot test. The results revealed that the ultraheavy oil in the LKQ oil field could achieve oxidation combustion under a high ignition temperature of greater than 450°C, where in-situ cracking and upgrading could occur, leading to greatly decreased viscosity of ultraheavy oil and significantly improved mobility. Moreover, it could achieve higher extra-heavy-oil production combined with the energy supplement of flue gas injection. The reasonable cycles of in-situ combustion huff and puff were five cycles, with the first cycle of gas injection of 300 000 m3 and the gas injection volume per cycle increasing in turn. It was predicted that the incremental oil production of a single well would be 500 t in one cycle. In addition, the supporting technologies were developed, such as a coiled-tubing electric ignition system, an integrated temperature and pressure monitoring system in coiled tubing, anticorrosion cementing and completion technology with high-temperature and high-pressure thermal recovery, and anticorrosion injection-production integrated lifting technology. The proposed method was applied to a pilot test in the YS3 well in the LKQ oil field. The high-pressure ignition was achieved in the 2200-m-deep well using the coiled-tubing electric igniter. The maximum temperature tolerance of the integrated monitoring system in coiled tubing reached up to 1200°C, which provided the functions of distributed temperature and multipoint pressure measurement in the entire wellbore. The combination of 13Cr-P110 casing and titanium alloy tubing effectively reduced the high-temperature and high-pressure oxygen corrosion of the wellbore. The successful field test of the comprehensive supporting engineering technologies presents a new approach for effective production in deep extra-heavy-oil reservoirs.


Author(s):  
A.T. Zaripov ◽  
◽  
D.K. Shaikhutdinov ◽  
A.A. Bisenova ◽  
◽  
...  

Author(s):  
A. Larin
Keyword(s):  
The One ◽  

The author attempts to compare some key aspects of modernization in Taiwan, on the one hand, and Russia and China, on the other hand. The aim is to understand what provided the efficiency of the Taiwan version and to what extent the Taiwanese experience can be useful for our country. Despite all differences between Taiwan and Russia, the author believes, the essence of modernization in both cases is common, because the general objectives are the same.


2021 ◽  
Author(s):  
Eric Cayeux ◽  
Sigmund Stokka

Abstract Torque and drag models have been used for many decades to calculate tensions and torques along drill-strings, casing strings and liner strings. However, when applied to sand-screens, it is important to check that all the initial hypotheses used for torque and drag calculations are still valid. In particular, it should be checked whether the buoyancy force on a perforated tube may differ from the one applied to a plain tube. The buoyancy force applied on a pipe, contributes to the sum of efforts at the contact between the pipe and the borehole and therefore influences torque and drag calculations. This contact force is local and should account for localized effects as well as the material internal forces, torques and moments on each side of the contact. As the buoyancy force is the result of the gravitational component of the pressure gradient on the surface of the pipe that is in contact with the fluid, the presence of holes in the pipe also influences the buoyancy force. When applied to a portion of a pipe, buoyancy does not have contributions at the end caps of that portion of the drill-stem since these end caps are not in contact with the fluid, except at positions with a change of diameter. Therefore, one shall be cautious when calculating the local buoyancy force either on a plain or a perforated tube. The paper describes how to calculate the local buoyancy force on a portion of a drill-stem by application of the Gauss theorem accounting for the necessary corrections arising from the end caps not being exposed to the fluid. An experimental setup has been built to verify that the tension inside a pipe subject to buoyancy does follow the derived mathematical calculations. With complex well construction operations, for instance during extended reach drilling or when drilling very shallow wells with high kick-off rates, the slightest error in torques and drag calculations may end up in jeopardizing the chance of success of the drilling operation. It is therefore important to check that all initial calculation hypotheses are still valid in those contexts and that for instance, sand-screens may be run in hole safely after a successful drilling operation.


2021 ◽  
Author(s):  
Xueqing Tang ◽  
Ruifeng Wang ◽  
Zhongliang Cheng ◽  
Hui Lu

Abstract Halfaya field in Iraq contains multiple vertically stacked oil and gas accumulations. The major oil horizons at depth of over 10,000 ft are under primary development. The main technical challenges include downdip heavy oil wells (as low as 14.56 °API) became watered-out and ceased flow due to depleted formation pressure. Heavy crude, with surface viscosities of above 10,000 cp, was too viscous to lift inefficiently. The operator applied high-pressure rich-gas/condensate to re-pressurize the dead wells and resumed production. The technical highlights are below: Laboratory studies confirmed that after condensate (45-52ºAPI) mixed with heavy oil, blended oil viscosity can cut by up to 90%; foamy oil formed to ease its flow to the surface during huff-n-puff process.In-situ gas/condensate injection and gas/condensate-lift can be applied in oil wells penetrating both upper high-pressure rich-gas/condensate zones and lower oil zones. High-pressure gas/condensate injected the oil zone, soaked, and then oil flowed from the annulus to allow large-volume well stream flow with minimal pressure drop. Gas/condensate from upper zones can lift the well stream, without additional artificial lift installation.Injection pressure and gas/condensate rate were optimized through optimal perforation interval and shot density to develop more condensate, e.g. initial condensate rate of 1,000 BOPD, for dilution of heavy oil.For multilateral wells, with several drain holes placed toward the bottom of producing interval, operating under gravity drainage or water coning, if longer injection and soaking process (e.g., 2 to 4 weeks), is adopted to broaden the diluted zone in heavy oil horizon, then additional recovery under better gravity-stabilized vertical (downward) drive and limited water coning can be achieved. Field data illustrate that this process can revive the dead wells, well production achieved approximately 3,000 BOPD under flowing wellhead pressure of 800 to 900 psig, with oil gain of over 3-fold compared with previous oil rate; water cut reduction from 30% to zero; better blended oil quality handled to medium crude; and saving artificial-lift cost. This process may be widely applied in the similar hydrocarbon reservoirs as a cost-effective technology in Middle East.


2021 ◽  
Vol 2 (2) ◽  
pp. 75
Author(s):  
Harry Budiharjo Sulistyarso ◽  
KRT Nur Suhascaryo ◽  
Mochamad Jalal Abdul Goni

The MRA platform is one of the offshore platforms located in the north of the Java Sea. The MRA platform has 4 production wells, namely MRA-2ST, MRA-4ST, MRA-5, and MRA-6 wells. The 4 production wells are produced using an artificial lift in the form of a gas lift. The limited gas lift at the MRA Platform at 3.1 MMSCFD makes the production of wells at the MRA Platform not optimal because the wells in the MRA Platform are experiencing insufficient gas lift. Optimization of gas lift injection is obtained by redistribution of gas lift injection for each. The results of the analysis in this study indicate that the optimum gas lift injection for the MRA-2ST well is 0.5552 MMSCFD, the MRA-6 well is 1.0445 MMSCFD, the MRA-5 well is 0.7657 MMSCFD, finally the MRA-4ST well with gas injection. lift is 0.7346 MMSCFD. The manual gas lift in the MRA-4ST is also replaced based on an economic feasibility analysis to ensure that the gas lift injection for each well can be kept constant. The redistribution of gas lift carried out by the author has increased the total production rate of the MRA Platform by 11,160 BO/year or approximately USD 781,200/year. Keywords: Gas lift; Insufficient; Optimization


2018 ◽  
Vol 2 (1) ◽  
pp. 32
Author(s):  
Mia Ferian Helmy

Gas lift is one of the artificial lift method that has mechanism to decrease the flowing pressure gradient in the pipe or relieving the fluid column inside the tubing by injecting amount of gas into the annulus between casing and tubing. The volume of  injected gas was inversely proportional to decreasing of  flowing  pressure gradient, the more volume of gas injected the smaller the pressure gradient. Increasing flowrate is expected by decreasing pressure gradient, but it does not always obtained when the well is in optimum condition. The increasing of flow rate will not occured even though the volume of injected gas is abundant. Therefore, the precisely design of gas lift included amount of cycle, gas injection volume and oil recovery estimation is needed. At the begining well AB-1 using artificial lift method that was continuos gas lift with PI value assumption about 0.5 STB/D/psi. Along with decreasing of production flow rate dan availability of the gas injection in brownfield, so this well must be analyze to determined the appropriate production method under current well condition. There are two types of gas lift method, continuous and intermittent gas lift. Each type of gas lift has different optimal condition to increase the production rate. The optimum conditions of continuous gaslift are high productivity 0.5 STB/D/psi and minimum production rate 100 BFPD. Otherwise, the intermittent gas lift has limitations PI and production rate which is lower than continuous gas lift.The results of the analysis are Well AB-1 has production rate gain amount 20.75 BFPD from 23 BFPD became 43.75 BFPD with injected gas volume 200 MSCFPD and total cycle 13 cycle/day. This intermittent gas lift design affected gas injection volume efficiency amount 32%.


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