Lessons Learnt from Integrated Production Modelling and Performance Analysis of Gas Lift Wells of One of the Biggest Offshore Complexes in India

2021 ◽  
Author(s):  
Sagun Devshali ◽  
Ravi Raman ◽  
Sanjay Kumar Malhotra ◽  
Mahendra Prasad Yadav ◽  
Rishabh Uniyal
Keyword(s):  
Performance Analysis ◽  
Flow Line ◽  
Gas Injection ◽  
Injection Rate ◽  
Oil Wells ◽  
Nodal Analysis ◽  
Integrated Production ◽  
And Performance ◽  
Gas Lift ◽  
Production Modelling

Abstract The paper aims to discuss various issues pertaining to gas lift system and instabilities in low producer wells along with the necessary measures for addressing those issues. The effect of various parameters such as tubing size, gas injection rate, multi-porting and gas lift valve port diameter on the performance analysis of integrated gas lift system along with the flow stability have been discussed in the paper. Field X is one of the matured offshore fields in India which has been producing for over 40 years. It is a multi-pay, heterogeneous and complex reservoir. The field is producing through six Process Complexes and more than 90% of the wells are operating on gas lift. As most of the producing wells in the field are operating on gas lift, continuous performance analysis of gas lift to optimize production is imperative to enhance or sustain production. 121 Oil wells and 7 Gas wells are producing through 18 Wellhead platforms to complex X1 of the field X. Out of these 121 oil wells, 5 are producing on self and remaining 116 with gas lift. In this paper, performance analysis of these 116 flowing gas lift wells, carried out to identify various problems which leads to sub-optimal production such as inadequate gas injection, multi-porting, CV choking, faulty GLVs etc. has been discussed. On the basis of simulation studies and analysis of findings, requisite optimization/ intervention measures proposed to improve performance of the wells have been brought out in the paper. The recommended measures predicted the liquid gain of about 1570 barrels per day (518 barrels of oil per day) and an injection gas savings in the region of about 28 million SCFD. Further, the nodal analysis carried out indicates that the aforementioned gas injection saving of 28 million SCFD would facilitate in minimizing the back pressure in the flow line network and is likely to result in an additional production gain of 350 barrels of liquid per day (65 barrels of oil per day) which adds up to a total gain of 1920 barrels of liquid per day (583 barrels of oil per day). Additionally, system/ nodal analysis has also been carried out for optimal gas allocation in the field through Integrated Production Modelling. The analysis brings out a reduction in gas injection by 46 million SCFD with likely incremental oil gain of ~100 barrels of oil per day.

Computational Fluid Dynamics for Gas Lift Optimization in Highly Deviated Wells

2021 ◽  
Author(s):  
Farasdaq Sajjad ◽  
Steven Chandra ◽  
Alvin Wirawan ◽  
Silvya Dewi Rahmawati ◽  
Michelle Santoso ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Gas Flow ◽  
Flow Behavior ◽  
Gas Injection ◽  
Injection Rate ◽  
Production Loss ◽  
Valve Placement ◽  
Offshore Field ◽  
Gas Lift

Abstract In the implementation of gas lift, understanding flow behavior in highly-deviated well is critical in avoiding production loss due to liquid fallback and blockage, even in highly-productive reservoir. In this work, we utilize Computational Fluid Dynamics (CFD) to optimize gas lift design under various flow behavior in highly-deviated well. The analysis is directly implemented into Arjuna offshore field case. Arjuna offshore field has gas-lifted wells, producing from a high-permeability reservoir. However, several wells suffer from huge production loss due to the effect of well's deviation. In deviated well, there exists frequent liquid fallback causes blockage, therefore, reducing the production. Motivated by this issue, we use CFD framework to perform gas lift optimization. We firstly adopt the geometry of gas-lifted wells as the computational domains for our simulation. An image-based meshing technique is deployed to capture the well's trajectory and internal geometry. We secondly utilize compressible Navier-Stokes equation and Finite Volume Method to evaluate the flow behavior. We capture the location of liquid fallback and liquid accumulation at elbows to estimate production loss. We consider the variation of viscosity, density, gas lift valve placement, injected gas rate, and reservoir pressure. We finally perform gradient-based optimization utilizing production loss as the objective function to obtain optimum design. The final result is then used to optimize the current design. The simulation results show that productivity index, pipe diameter, and deviation heavily influence the amount of production loss. At big pipe diameter and high deviation, the gravitational force governs the fluid flow. Therefore, slugs are developed and accumulated at elbows. This accumulation blocks gas flow and reduces production. Changing the gas injection rate affects the lifted density. High injection rate triggers segregation between the liquid and gas, while low injection rate does not reduce the liquid density. Shifting the gas lift valve placement influence the mixing between the liquid and gas. It also determines the cost of gas injection. Hence, we need to optimize both parameters at once. Six of thirty wells in Arjuna field experience severe liquid fallback, therefore, the production significantly decreases. The simulation shows up to 40% coverage of the pipe internal diameter, which blocks the gas flow. We perform the optimization by shifting the gas lift valve placement and adjusting the gas injection rate. By implementing the study result into the field case, we manage to improve the production by 20%. We provide an effective way to connect high-resolution simulation to the field design and revise the current concept in designing gas lift well completion. The simulation allows engineers to provide more insight on flow assurance in highly deviated wells.

scholarly journals An Investigation on Gas Lift Performance Curve in an Oil-Producing Well

2007 ◽  
Vol 2007 ◽  
pp. 1-15 ◽  
Author(s):  
Deni Saepudin ◽  
Edy Soewono ◽  
Kuntjoro Adji Sidarto ◽  
Agus Yodi Gunawan ◽  
Septoratno Siregar ◽  
...  
Keyword(s):  
Production Rate ◽  
Gas Injection ◽  
Oil Production ◽  
Injection Rate ◽  
Performance Curve ◽  
Production Well ◽  
Phase Liquid ◽  
Two Phases ◽  
Gas Lift ◽  
Operation Cost

The main objective in oil production system using gas lift technique is to obtain the optimum gas injection rate which yields the maximum oil production rate. Relationship between gas injection rate and oil production rate is described by a continuous gas lift performance curve (GLPC). Obtaining the optimum gas injection rate is important because excessive gas injection will reduce production rate, and also increase the operation cost. In this paper, we discuss a mathematical model for gas lift technique and the characteristics of the GLPC for a production well, for which one phase (liquid) is flowing in the reservoir, and two phases (liquid and gas) in the tubing. It is shown that in certain physical condition the GLPC exists and is unique. Numerical computations indicate unimodal properties of the GLPC. It is also constructed here a numerical scheme based on genetic algorithm to compute the optimum oil production.

scholarly journals Gas lift optimization in the oil and gas production process: a review of production challenges and optimization strategies

2020 ◽  
Vol 1 (2) ◽  
pp. 61
Author(s):  
Ikenna Tobechukwu Okorocha ◽  
Chuka Emmanuel Chinwuko ◽  
Chika Edith Mgbemena ◽  
Chinedum Ogonna Mgbemena
Keyword(s):  
Production Process ◽  
Oil And Gas ◽  
Gas Injection ◽  
Injection Rate ◽  
Gas Production ◽  
Optimization Techniques ◽  
Oil Well ◽  
Oil And Gas Production ◽  
Artificial Lift ◽  
Gas Lift

Gas Lift operation involves the injection of compressed gas into a low producing or non-performing well to maximize oil production. The oil produced from a gas lift well is a function of the gas injection rate. The optimal gas injection rate is achieved by optimization. However, the gas lift, which is an artificial lift process, has some drawbacks such as the deterioration of the oil well, incorrect production metering, instability of the gas compressor, and over injection of gas. This paper discusses the various optimization techniques for the gas lift in the Oil and Gas production process. A systematic literature search was conducted on four databases, namely Google Scholar, Scopus, IEE Explore and DOAJ, to identify papers that focused on Gas lift optimizations. The materials for this review were collected primarily via database searches. The major challenges associated with gas lift were identified, and the different optimization strategies available in the literature reviewed. The strategies reviewed were found to be based on artificial intelligence (AI) and machine learning (ML). The implementation of any of the optimization strategies for the gas lift will enhance profitability, reduce operational cost, and extend the life of the wells.

scholarly journals Multi-Objective Gas Lift Optimization using Elitist Non-Dominated Sorting Genetic Algorithm (NSGA-II)

2019 ◽  
Vol 8 (4) ◽  
pp. 9737-9740
Keyword(s):  
Production Rate ◽  
Production Cost ◽  
Gas Injection ◽  
Oil Production ◽  
Injection Rate ◽  
Nsga Ii ◽  
Wellhead Pressure ◽  
Multi Objective ◽  
The Cost ◽  
Gas Lift

In petroleum industry, gas lift optimization is the most important for evaluating the reservoir. By improving the gas lift operation we can save money and time which we spend on the reservoir for effective production. The mainly accepted scenario of gas lift is to maximize production by using minimized cost infrastructure. If the production rate is increased, then the cost of oil production also increases due to the increase in surface facilities and increase in cost of gas compression to higher pressures. The production rate and production cost during gas lift are mutually conflicting in nature i.e., if anyone desires to increase the oil production rate, then at the same time it is difficult to minimize the cost of production. Therefore, this is an ideal candidate for multi-objective optimization study, where production rate needs to maximized while minimizing the cost of production. The oil production rate is calculated using nodal analysis of inflow performance and outflow performance curve while the production cost is calculated using the brake horsepower requirement of the compressor. Oil production rate during a gas lift operation can be defined as a function of various factors like (i) depth of gas injection, (ii) gas injection rate (iii) gas lift injection pressure, (iv) wellhead pressures, (v) bottom hole pressure, (vi) tubing size, (vii) surface choke size/wellhead pressure. Production cost mainly depends on the cost of gas compression which further depends on the pressure up to which gas has to be compressed in the annulus so that the gas lift valve at the bottom of the well opens. The opening of gas lift valve depends on the bottom hole pressure in the tubing i.e. the density of mixture present inside the tubing. The multi-objective gas lift optimization is carried out using multi-objective evolutionary algorithms (EAs) that use non-dominated sorting called elitist non-dominated sorting genetic algorithm (NSGA-II). In this project, we aim to find the optimum values of the decision parameters i.e. gas injection rate and wellhead pressure, for which oil production rate would be maximized while minimizing the cost of oil production.

scholarly journals GAS LIFT OPTIMIZATION OF A MATURE WELL IN NIGER DELTA, NIGERIA USING INCOMPLETE DATASET: A CASE STUDY

2020 ◽  
Vol 4 (1) ◽  
pp. 15-18
Author(s):  
Oghenegare E. Eyankware ◽  
Idaereesoari Harriet Ateke ◽  
Okonta Nnamdi Joseph
Keyword(s):  
Niger Delta ◽  
Gas Injection ◽  
Injection Rate ◽  
Wellhead Pressure ◽  
Well Production ◽  
Artificial Lift ◽  
Lift Mechanism ◽  
Fluid Production ◽  
Water Cut ◽  
Gas Lift

Well DEF, a well located in Niger Delta region of Nigeria was shut down for 7 years. On gearing towards re-starting production, different options such as installation of gas lift mechanism, servicing and installation of packers and valves were evaluated for possibility of increasing well fluid productivity. Hence, this research was focused on optimizing well fluid productivity using PROSPER through installation of continuous gas lift mechanism on an existing well using incomplete dataset; in addition, the work evaluated effect of gas injection rates, wellhead pressure, water cut and gas gravity on efficiency of the artificial lift mechanism for improved well fluid production. Results of the study showed that optimum gas injection rate of 0.6122 MMscf/day produced well fluid production of 264.28 STB/day which is lower than pristine production rate (266 STB/day) of the well. Also, increment in wellhead pressure resulted in decrease in well production, increase in water cut facilitated reduction in well fluid productivity while gas gravity is inversely proportional to well fluid productivity. Based on results obtained, authors concluded that Well DEF does not require gaslift mechanism hence, valves and parkers need to be re-serviced and re-installed for sustained well fluid.

Real-Time Gas Lift Well Optimization Using Surface Read Out (SRO) System in Bunyu Field

2021 ◽  
Author(s):  
C. F. Amiin
Keyword(s):  
Real Time ◽  
Gas Injection ◽  
Injection Rate ◽  
Performance Model ◽  
Rate Variation ◽  
Production Test ◽  
Total Production ◽  
Well Performance ◽  
Production Forecast ◽  
Gas Lift

Gas lift optimization is required to sustain production in Bunyu Field. There are 35 gas lifted wells from total of 61 production wells, which contribute to2916 BOPD from the total production of 6000 BOPD or around 49% of the total production. The performance of these wells are pivotal to ensure production target is achieved. An optimum gas injection rate in each well is essential to maximize the oil production by reducing the Flowing Bottom Hole Pressure (FBHP). Previously, a conventional downhole Pressure – Temperature (P-T) gauge was used to record well response to gas lift injection rate variation to determine the optimum point. However, this method is considered time consuming since the adjustment to determine the optimum gas injection rate can only be done after the data has been downloaded and being analyzed . Thus, the measurement program should be repeated several times until the optimum gas injection rate is determined. This paper presents an approach to optimize the production of gas lifted well by selecting the optimum gas injection rate using a real-time downhole data monitoring system, called Surface Read Out (SRO). This system is used to evaluate the changes in the downhole pressure and temperature in a real-time. When the downhole P-T gauge reaches the perforation depth, a Multi-Rate Test (MRT) is carried out with variation in gas injection rate to find the optimum rate. Optimum gas injection rate is then determined based on the lowest FBHP observed and the highest production test result during the MRT. This optimization method has been proven effective to quickly increasing well production because gas injection rate adjustment can be done during the measurement program based on the real-time analysis. In addition, calibration of well performance model based on the actual Gas Lift Performance Curve (GLPC) of the MRT result can provide more accurate production forecast.

scholarly journals Application of Mechanistic Modeling for Gas Lift Optimization: A General Scaling Curve for Variations of Tubing Size to Optimum Gas Injection

2019 ◽  
Vol 8 (2) ◽  
pp. 40-48
Author(s):  
Prasandi Abdul Aziz ◽  
Ardhi Hakim Lumban Gaol ◽  
Wijoyo Niti Daton ◽  
Steven Chandra
Keyword(s):  
Flow Pattern ◽  
Correction Factor ◽  
Gas Injection ◽  
Oil Wells ◽  
Mechanistic Modeling ◽  
New Approach ◽  
Flow Pattern Map ◽  
Artificial Lift ◽  
Performance Curves ◽  
Gas Lift

Gas Lift is currently held as one of the most prominent method in artificial lift, proudly operated flawlessly in hundreds of oil wells in Indonesia. However, gas lift optimization is still governed by the exhaustive Gas Lift Performance Curves (GLPC). This practice, albeit as established as it should be, does require repetitive calculations to be able to perform in life of well operations. Therefore, a new approach is introduced based on the mechanistic modeling. This research highlights the application of fundamental mechanistic modeling and its derivative, the Flow Pattern Map (FPM) for quick estimation of optimum injection gas rate, accompanied by a novel correction factor to account changing tubing sizes. It is hoped that this approach can be beneficial in developing a multitude of gas lift wells with changing tubing sizes.

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