Improved Oil and Gas Recovery

Coalbed Methane Potential of Pakistan-A Review

Wed, 20 Dec 2023 00:00:00 -0700

The continuous decrease in gas reserves and increase in natural gas demand forces Pakistan to explore new reserves. Coalfields in the country offer potential availability of gas reserves in the form of coalbed methane (CBM). These coalfields can accommodate gas demand of the country in long-terms. CBM is a clean energy source and shows a complex storage mechanism as compared to conventional gas reserves. Hence, modern techniques are required for its exploitation. This paper provides a review and analysis of literature for CBM and CO₂-ECBM production from the largest coalfield. Based on available data, similarity among different coalfields assist in calculating potentiality of CBM. The study investigates production potential of CBM and CO₂-ECBM in Thar coalfields. The CO₂ injection can enhance CBM production, and a significant amount of CO₂ can be stored because of process. Being largest coal reserves in the country, the investigation concludes that Thar coalfield can accommodate the country's gas demand. This study proposes technical recommendations for practical implications of large-scale development of CBM and CO₂-ECBM subjected to the in-depth calculation of gas adsorption, gas content, and optimum depth for CO₂ injection.

Experimental Work of Nanoparticles-assisted Water Flooding

Ahmed Moawad Ahmed — Fri, 22 Mar 2024 00:00:00 -0600

The Nanoparticle is of great importance in enhancing oil extraction. The increasing oil demand pushed scientists to think of new technology to enhance oil recovery. The nanoparticle, which reaches a scale of 1-100 nanometers, is an influential element in maximizing oil production. Nanoparticles help recover crude oil by several mechanisms such as wettability alteration of the porous media, interfacial tension reduction, disjoining pressure, and mobility ratio reduction. This research introduces the effects of different nanoparticles such as silica, iron oxide, zinc oxide, and mixed nanoparticles on oil recovery. The results showed that nanoflooding improves oil recovery more than conventional water flooding.

Optimization of Oil-Gas Separation in the Production Stations at Abo-Sannan Field: Case Study

Mohamed Kotb, Galal Abdelalim, Said Abdall — Wed, 27 Dec 2023 00:00:00 -0700

The study employs Aspen HYSYS simulation and optimization tools to investigate three different scenarios. This optimization aims to determine the optimal separator pressures for a two-stage gas-oil separation plant (GOSP) as well as modified configurations for three- and four-stage separations while targeting maximum profit and best results.

The study consists of three case scenarios. The first case study deals with the existing base station under normal and optimal operating conditions. The second case study involves modifying an existing T-oil plant by rearranging the separators to create sequential separators that operate under ideal conditions. The third case study explores adding one additional separator in series to the three existing separators in the series, all of which operate under optimal conditions. Extracting oil and gas, reducing energy consumption. The crude oil Reed Vapor Pressure (RVP) is set to 10 psi for all scenarios.

This study resulted in significant improvements, including a daily increase in oil recovery of 1.8%, 2.3% and 2%, as well as a daily increase in net profit of 6.4%, 5.8% and 4.3%, respectively. Specifically, simulations conducted in the three case studies revealed significant daily increases in oil recovery also highlight the potential for improved performance and economic benefits through improved T-oil plant and GOSP operations, contributing to a more sustainable and profitable crude oil processing industry.

The crude oil stabilization unit known as the T-oil plant within the Gas-Oil Separation Plant (GOSP) is greatly enhanced by using the multiple separation stages.

Parametric Evaluation on the Interfacial Tension Response of Agro-Surfactant

Tue, 23 Apr 2024 00:00:00 -0600

The introduction of surface active agent such as surfactants reduces interfacial tension (IFT) between the oil-water systems to yield higher oil recovery. This reduction continues with surfactant concentration until the critical micelle concentration is attained. The IFT reduction capacity of surfactant in brine-oil system is impacted by the surfactant concentration, salt concentration, temperature variation and polymer concentration. In this study, parametric evaluation was conducted to determine the impact salinity, temperature and polymer on the IFT value of costus afer extracts (CAE), vernonia amygdalina extract (VAE), carica papaya extract (CPE) and sodium lauryl sulfate ?SLS?. From the result of IFT at varying salinity, CAE, VAE and CPE is not suitable for high saline environment. From the result of IFT at varying temperature, CAE and CPE have dominant nonionic properties, while VAE showed dominant anionic properties. From the result of IFT at varying polymer, polymer introduction reduces the IFT value of the surfactants.

Exploring Influential Factors for Composite Flooding with Polymer Viscosity Reducers in Heavy Oils

Fri, 17 Nov 2023 00:00:00 -0700

Extracting heavy oil presents significant challenges due to its high viscosity, poor fluidity, elevated asphaltene content, and the complexities involved in its development. Traditional extraction methods often fall short of meeting the developmental needs for such oil. Currently, the use of polymer viscosity reducer composite flooding technology has shown promising results both domestically and internationally in heavy oil extraction. While the prospects for this technology are encouraging, there is limited research on the primary factors of the polymer viscosity reducer affecting oil recovery, underscoring the need for further investigation.

A numerical model was formulated using the STARS module of CMG to assess the development of heavy oil extraction via viscosity reducer flooding, polymer flooding, and polymer with viscosity reducer composite flooding. The study contrasted the impacts of these varied injection methodologies on heavy oil recovery. Findings indicated that the composite flooding for the polymer and viscosity reducer enhanced the recovery rate by 48.22%, outperforming water flooding or single chemical flooding. Both single-factor analysis and orthogonal design were employed to assess variables such as injection slug, polymer mass concentration, mass concentration of viscosity reducer, timing of injection, and the rate of chemical composite flooding. In terms of enhancing oil recovery, the injection plug volume had the most pronounced impact on recovery, while the timing of injection has a minimal impact on efficiency.

This research furnishes crucial technical backing for the enhancement of heavy oil reservoirs through chemical composite flooding. It significantly advances the deployment and application of polymer viscosity reducer chemical composite flooding in similar reservoirs. Moreover, the findings are poised to offer pivotal references and direction for employing chemical composite flooding techniques in heavy oils.

Key Technology of Efficient Exploitation of Coalbed Methane in Qinshui Basin of CNOOC

Tue, 20 Feb 2024 00:00:00 -0700

Three key technologies have been developed for the development of coalbed methane in Qinshui Basin. The first technology is the gas content analysis technology coupled with isothermal adsorption theory and production dynamics. By fitting bottom-hole flow pressure and critical desorption pressure of coal reservoir, combined with the isothermal adsorption curve of coal reservoir, the gas content of the reservoir can be accurately predicted. This technique provides important geological parameters for evaluating coal reservoirs. The second technology is production system optimization technology based on reservoir seepage mechanism and numerical simulation analysis. Velocity sensitive response, stress sensitive effect and gas-water two-phase flow are considered in the process of production system optimization. By understanding the main contradictions in different production and discharge stages of coalbed methane wells and taking the final cumulative gas production and peak gas production as optimization objectives, the quantitative optimization method of coalbed methane drainage and production system is formed. One optimization system for each coalbed methane well and one optimization system for each day has been realized. This technology is used throughout the entire production cycle of a coalbed methane well. The third technology is the efficient development technology of horizontal well in coal seam with fractured coal structure.Through numerical simulation study, it is clear that No. 15 coal seam in Panhe Block is suitable for integrated horizontal well development. In the early stage of horizontal well drilling, problems such as wall instability, drilling depth of some wells is not up to the design, and the length of horizontal section of real drilling is not up to the design. Aiming at this problem, the stability model of borehole wall of Panhe River is established by using the four-dimensional geostress modeling technique. The model reveals that the collapse pressure of horizontal wells is higher than that of vertical wells, and complex accidents such as collapse block are more likely to occur. In view of this feature, suspension agent, drainage aid and inhibitor are selected to improve the return of pulverized coal pressure, promote the fracturing fluid backflow, reduce the viscosity of mineral collision, and select a new type of active water fracturing fluid system. The successful application of the three key technologies provides a strong support for the efficient development of coalbed methane in Qinshui Basin, and also provides a technical reference for the efficient development of other coalbed methane basins.

Prediction of Brine Hydrate Formation Temperature Using ANN-Based Model

Ahmed Elswisy, Mohsen Elnoby, Adel Salem — Tue, 20 Feb 2024 00:00:00 -0700

This study aims to use Artificial Neural Networks (ANN) to predict Hydrate Formation Temperature of the brine which is used of completion, workover, and well intervention operations. It seeks to build an ANN model with inputs weight percentages of the brine salts components, gas specific gravity, pressure, and gas impurities percentages (N₂, H₂s, Co₂) to produce the Hydrate Formation Temperature as an output with high accuracy for both divalent and monovalent brines by using real dataset of about 200 for monovalent brines and about 300 for divalent brines with good range, optimization processes are performed to determine the best configuration to be used in ANN, so it involves training function optimization and number of hidden neurons to be used in ANN models, so The novel ANN models in this study will give a correlation that can be used to estimate the HFT directly.

An Innovative Method for Comprehensive Optimization of Hydraulic Fracturing Parameters to Enhance Production in Tight Oil Reservoirs

Sun, 19 Nov 2023 00:00:00 -0700

The hydraulic fracturing technology for horizontal wells is one of the key techniques for the effective development of tight oil and gas reservoirs. Optimizing fracturing parameters can significantly enhance fracturing effectiveness, reduce development risks, and improve oil and gas production as well as economic efficiency. Rapid and accurate optimization of hydraulic fracturing construction parameters for tight oil horizontal wells has always been a challenge in reservoir development and management. This study introduces a novel workflow for optimizing fracturing parameters by combining reservoir numerical simulation and machine learning techniques. The paper first establishes a single-well numerical model using Petrel, and refines reservoir parameters through historical production matching. Building upon this, 8 parameters are selected, and an initial parameter set is generated using the Monte Carlo method, with production data sets obtained from reservoir numerical simulation. Subsequently, various methods are employed to construct fracture productivity models under different reservoir and hydraulic fracture parameters. The selected machine learning model is then integrated with an economic evaluation model to establish an optimization model for hydraulic fracturing parameters in tight oil horizontal wells. The research indicates that the production prediction model established based on the CNN-LSTM method exhibits a high level of accuracy. The optimization model for hydraulic fracturing parameters in tight oil horizontal wells can rapidly optimize fracturing parameters. The proposed methodology in the paper has the potential to enhance horizontal well production and improve economic benefits in tight oil horizontal wells, and can also be applied to similar field development and engineering parameter optimization scenarios.

Carbon Sequestration in Unmined Coalbeds of Pakistan

Osama Ajaz, Saleem Qadir Tunio, Jahangeer Zafar — Fri, 19 Apr 2024 00:00:00 -0600

Exponential increment in Carbon dioxide (CO2) emissions into the atmosphere has become a serious threat to global security. Many reports concluded that maintaining <2oC is mandatory to avoid severe consequences associated with the environment and global warming. Pakistan is indexed in a region of high vulnerability to climate change. Due to this, the country has faced severe reflection of the deteriorated environment in terms of drought, floods, and uncertain climatic conditions. The country’s recent development has increased emissions as many power plants are being run on coal. All this implies that significant efforts must be made to emphasize limiting emissions and environmental damage. Carbon storage technology is a way forward for continuous utilization of fossil fuels. Coalbeds ensure secure storage of CO2 for long term. Carbon storage in subsurface beds will minimize the ongoing greater impact on environment of Pakistan. Thar Coalfield offers great potential for CO2 storage due to the largest reserves in the country. This study contributes towards further steps needed for practical implementation of Carbon capture and sequestration in Thar coalfield. The analogy among different coal sites for carbon storage is drawn to project potential of Thar coalfield along with other coalfields in Pakistan. Thar coalfield properties, being lignite in rank, resemble North Dakota coalfield, whereas some properties resemble Rajasthan coals. Hence, North Dakota Coalfield and Rajasthan can be effective reference projects for practical implementation of CO2 storage in Thar coalfields. The research study has recommended further directions for study to calculate exact amount of CO2 storage. The study is concluded with the future implication of potential carbon storage in the coalfield of Thar.