Black-Oil and Compositional Reservoir Simulation of Gas-Based EOR in Tight Unconventionals

Mydland, Stian; Whitson, Curtis Hays; Carlsen, Mathias Lia; Dahouk, Mohamad Majzoub; Yusra, Ilina

doi:10.15530/urtec-2020-2765

Cited by 5 publications

(3 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During oil production, the formation of wax deposits also affects the status quo of the fluid flow. Furthermore, the viscosity of crude oil will increase, which consequently causes high demands in energy consumption for pumping processes, and as a result, the wax formation is the critical factor influencing the loss of efficiency [6][7][8][9]. The wax is composed of heavy hydrocarbons, the carbon numbers that change from 18 to 30, known as paraffin wax, which is mixture of linear and branched saturated hydrocarbons, and saturated cyclic naphthenic hydrocarbons with carbon numbers from 31 to 65.…”

Section: Introductionmentioning

confidence: 99%

An extensive solution to prevent wax deposition formation in gas-lift wells

Nguyen¹,

Александров²,

Рогачев³

2022

J Appl Eng Science

View full text Add to dashboard Cite

In recent years, an insurmountable problem in high-wax oil production has been the intensive formation of organic deposits in the bottom-hole zone of the formation, downhole and surface equipment, leading to a dramatic loss in wells production, transportation capability, and subsequently has a detrimental effect on efficiency. Gas-lift is a widely used method, where compressed high-pressure gas is injected through the tubing annulus. Consequently, the current fluid level in the annulus decreases and increases in the tubing string. The compressed gas enters the tubing through gas-lift valves, mixing with the liquid. During production, changes in pressure, temperature, and fluid composition along the well bore highly depend upon the compressed gas injected into the well. At temperatures below the wax appearance temperature, organic wax crystals will form either in bulk volumes of fluid or on cold surfaces of equipment, consequently, covering the surface. Wax formation is a hazardous and costly task in the oil and gas industry, especially when operating gas-lift wells. Hence, the prevention of wax formation in gas-lift wells is of utmost importance. Although, numerous methods have been implemented to handle the wax formation problem in recent decades, questions concerning their economic viability as well as their effectiveness remain relevant. In this paper, a complete algorithm for determining changes in the oil component composition in a gas-lift well during the injection of associated petroleum gas is detailed. The obtained results play a pivotal role in the study of wax deposition. A technological scheme has been developed to prevent wax deposit formation in the tubing strings during gas-lift well operation. A simulation using the introduced process and technology has been run, and an observed result obtained. After running the simulation, we determined the optimal composition of the associated petroleum injection gas based on the required flow rate of the working agent and the lowest value of the wax appearance temperature. This method offers potential solutions to increasing gas-lift well production efficiency under complex wax formation conditions.

show abstract

Section: Introductionmentioning

confidence: 99%

An extensive solution to prevent wax deposition formation in gas-lift wells

Nguyen¹,

Александров²,

Рогачев³

2022

J Appl Eng Science

View full text Add to dashboard Cite

show abstract

“…Chemical solvents are also employed when oils are susceptible to surfactants or produce water with a high concentration of dissolved solid particles. The well-known chemical solvents to dissolve wax deposits are carbon tetrachloride, carbon disulfide, kerosene, and diesel oil [30][31][32][33]. The most significant advantage of using chemical solvents is their pricing and the fact that they do not always require complicated instrumentation.…”

Section: Introductionmentioning

confidence: 99%

Technology for Preventing the Wax Deposit Formation in Gas-Lift Wells at Offshore Oil and Gas Fields in Vietnam

2021

View full text Add to dashboard Cite

Within the past few decades, the production of high-wax oils at offshore fields in Vietnam has been fraught with severe problems due to the intense formation of asphalt-resin-paraffin deposits (ARPD) in the downhole oil and gas equipment. The formation of organic wax deposits in the tubing string led to a significant decrease in gas-lift wells production, efficiency of compressor units, transport capacity of the piping systems, along with an increase in equipment failure. Subsequently, the efficiency of gas-lift wells dramatically decreased to less than 40% as a whole. The existing methods and technologies for combating organic wax deposit formation in downhole equipment have many advantages. However, their use in producing high-wax anomalous oil does not entirely prevent the wax formation in the tubing string and leads to a significant reduction in oil production, transport capacity, and treatment intervals. The results of theoretical and experimental studies presented in this article demonstrate that a promising approach to improve the efficiency of gas-lift wells during the production of high-wax oil is to use the technology of periodic injection of hot associated petroleum gas (APG) into the annulus of an oil-producing well. The effectiveness of the proposed method of combating wax formation in gas-lift wells highly depends on the combination of a few factors: the determination of wax deposit formation intensity in the well and the implementation of a set of preparatory measures to determine the optimal injection mode of hot APG (flow rate and injection depth) into the annulus between tubing strings and technological pipes. The injection depth of the hot APG should not be less than the depth of wax formation in the tubing string. The optimal injection rate of hot APG is determined by analyzing and mathematically modeling the APG injection system based on well-known thermodynamic laws.

show abstract

“…The availability of accurate, reliable mathematical models of the gas-lift process is vital for the design and operation of a gas-lift system. Conventional models of continuous gaslift processes applied a black-oil treatment of the hydrocarbon fluids (Carroll et al 1990;Schou et al 1991;Mydland et al 2020;Du et al 2018;Coutinho et al 2017;Zhao et al 2017). Those models are unreliable due to the multiphase flow regime of the oil and gas mixture and consequently, the pressure drop in the wellbore is highly composition dependent.…”

Section: Introductionmentioning

confidence: 99%

A new approach to improving efficiency of gas-lift wells in the conditions of the formation of organic wax deposits in the Dragon field

Nguyen

Рогачев

Александров

2020

J Petrol Explor Prod Technol

View full text Add to dashboard Cite

Gas-lift is one of the artificial methods in which gas is injected down the production casing–tubing annulus and enters the production tubing through a number of gas-lift valves. During the production of a gas-lift well, the injected compressed gas might cause changes in pressure, temperature as well as fluid composition. When the temperature of the oil falls below the wax appearance temperature, it leads to the formation of organic wax deposits. Wax precipitation in well tubing and processing equipment might lead to dramatic reduction in production, equipment failures, loss of storage and transport capacity, and loss of efficiency. This paper presents a detailed study of wax formation in a gas-lift well. Taking into account changes in the oil component composition during gas injection, the depth of wax formation has been determined by applying a highly accurate developed algorithm. The optimal operating regime of the gas-lift well has been determined using a compositional multiphase model.

show abstract

Black-Oil and Compositional Reservoir Simulation of Gas-Based EOR in Tight Unconventionals

Cited by 5 publications

References 20 publications

An extensive solution to prevent wax deposition formation in gas-lift wells

An extensive solution to prevent wax deposition formation in gas-lift wells

Technology for Preventing the Wax Deposit Formation in Gas-Lift Wells at Offshore Oil and Gas Fields in Vietnam

A new approach to improving efficiency of gas-lift wells in the conditions of the formation of organic wax deposits in the Dragon field

Contact Info

Product

Resources

About