Papers by Ala'a AL-Dogail
This study proposes a novel discrete-time integral sliding mode control (ISMC) framework for mana... more This study proposes a novel discrete-time integral sliding mode control (ISMC) framework for managing pressure in multi-phase flow systems (MPFS), a critical component of hydrocarbon production and transportation. The primary goal is to achieve precise pressure regulation and minimize fluctuations under diverse operational conditions. Unlike traditional approaches, this work employs a Hammerstein nonlinear modeling technique to accurately represent the system dynamics and design the control strategy. The contributions of this research include the development of a data-driven system identification methodology using a single-input, single-output (SISO) Hammerstein model, enabling precise pressure prediction based on experimental data collected from the lab. A robust ISMC algorithm is introduced to address the inherent nonlinearities, disturbances, and uncertainties in multi-phase flow dynamics. The proposed controller is comprehensively validated through numerical simulations and experimental data, demonstrating its capability to reduce pressure fluctuations, enhance stability, and maintain operational efficiency. This novel integration of Hammerstein modeling with discrete-time ISMC offers a scalable and reliable solution to the challenges of pressure control in MPFS. The results demonstrate significant advantages over conventional controllers, such as traditional sliding mode, in terms of robustness and precision, contributing to the safety, efficiency, and sustainability of oil and gas operations.
Accurate prediction of pressure drops in multi-phase flow systems is essential for optimizing pro... more Accurate prediction of pressure drops in multi-phase flow systems is essential for optimizing processes in industries such as oil and gas, where operational efficiency and safety depend on reliable modeling. Traditional models often need help with the complexities of multi-phase flow dynamics, resulting in high relative errors, particularly under varying flow regimes. In this study, we simulate a comprehensive multiphase flow experimental data collected from the lab. This study presents innovative methods for accurately modeling pressure drops in multi-phase flow systems. It also studies the complicated dynamics of multi-phase flows, which are flows with more than one phase at the same time. It does this by using two different data-driven models, nonlinear ARX and Hammerstein-Wiener, instead of neural networks (NNs), so that the models don't get too good at fitting environments with lots of changes and little data. Our research applies system identification approaches to the intricacies of this domain, providing new insights into choosing the best appropriate modeling strategy for multi-phase flow systems, taking into account their distinct properties. The experimental results show that the nonlinear Hammerstein-Wiener and ARX models were much better than other methods, with fitting accuracy rates of 81.12% for the Hammerstein-Wiener model and 86.52% for the ARX model. This study helps the creation of more advanced control algorithms by providing a reliable way to guess when the pressure drops and showing how to choose a model that fits the properties of the multi-phase flow. These findings contribute to enhanced pressure management and optimization strategies, setting a foundation for future studies on real-time flow control and broader industrial applications.
ACS Omega, 2023
Matrix acidizing is a technique that is widely used in the petroleum industry to remove scales an... more Matrix acidizing is a technique that is widely used in the petroleum industry to remove scales and create channels in the rock. Removal of scales and creation of channels (wormhole) enhance productivity. Conventional acidizing fluids, such as hydrochloric acid (HCl) for carbonate and a mixture of hydrofluoric acid (HF) and HCl acid, are used for the matrix acidizing process. However, these fluids have some drawbacks, including strong acid strength, corrosion at high temperatures, and quick reactions with scale and particles. Emulsified acid systems (EASs) are used to address these drawbacks. EASs can create deeper and narrower wormholes by reducing the reaction rate of the acid due to the external oil phase. However, EASs have a much higher viscosity compared to conventional acidizing fluids. The high viscosity of EASs leads to a high drag that restricts pumping rates and consumes energy. This study aims to utilize environmentally friendly and widely available nanomaterials as drag-reducing agents (DRAs) of the EAS. The nanomaterials used in this study are carbon nanodots (CNDs). CNDs have unique properties and are used in diverse applications in different industries. The size of these CNDs is usually smaller than 10 nm. CNDs are characterized by their biocompatibility and chemical stability. This study investigates the use of CNDs as DRAs for EAS. Several experiments have been conducted to investigate the CNDs as a DRA for the EAS. The developed EAS was initially tested for conductivity and drop-test analysis to ensure the formation of an inverted emulsion. Thereafter, the thermal stability for the range of temperatures and the rheological properties of the EAS were evaluated to meet the criteria of field operation. Then flow experiments with EASs were conducted before and after adding the CNDs to investigate the efficacy of drag reduction of EASs. The results revealed that CNDs can be used as viscosity reducers for the EAS, where adding the CNDs to the EAS reduces the viscosity at two different HCl concentrations (15 and 20%). It reduces the viscosity of the EAS in the presence of corrosion inhibitors as well as other additives to the EAS, showing its compatibility with the field formulation. The drag reduction was observed at the range of temperatures investigated in the study. The conductivity, stability, and rheology experiments for the sample taken after the flow experiment are consistent, ensuring CNDs work as a DRA. The developed EAS with CNDs is robust in terms of field mixing procedures and thermally stable. The CNDs can be used as a DRA with EAS, which will reduce drag in pipes, increasing pumping rates and saving energy.
SPE Production & Operations
Summary Maximizing oil recovery of the gas-oil separation plant (GOSP) is intended to increase re... more Summary Maximizing oil recovery of the gas-oil separation plant (GOSP) is intended to increase revenue in the oil and gas industry. The GOSP is an integral part of the petroleum industry, and it consists of multistage separators, a heater-treater, desalination, a stabilization column, and a stock tank of oil. It is conventional practice to operate the GOSP at fixed operating conditions without considering the effects of variation for different parameters such as ambient temperature, chemical composition, reboiler (60°C, 65°C, and 70°C), and stabilization (temperature and pressure). Optimizing the GOSP parameters can help to maximize the GOSP oil recovery and, as a result, increase the revenue and profit. This study aims to optimize operation parameters to maximize the oil recovery of the GOSP at which the maximum oil recovery can be obtained from the GOSP. To achieve the objective of this study, first, a GOSP model was built using Petro-SIM process simulator software for a typical S...
Day 1 Mon, March 13, 2023, Mar 13, 2023
Day 2 Tue, March 14, 2023
Matrix acidizing technique is used to enhance the production of hydrocarbons from a reservoir, es... more Matrix acidizing technique is used to enhance the production of hydrocarbons from a reservoir, especially in low permeable reservoirs and in the case of formation damage. In carbonate reservoirs, acid stimulation jobs are challenging due to the acid's strong reactivity with the formation. Thus, the ability to create wormholes will be limited. Wormholes allow hydrocarbons to be produced by flowing into the wellbore. Emulsified acids system helps to overcome this challenge by reducing face dissolution. Recently, Pickering emulsions have attracted attention due to their easy preparation and enhanced stability features. In Pickering emulsions, solid microparticles that localize at the interface between liquids are used as stabilizers instead of surfactants. The preparation of emulsified acid system (EAS) is a complex process sensitive to several parameters governing the properties/feature of the emulsified system. The parameter includes mixing the aqueous and oleic phase, the rotati...
Arabian journal for science and engineering, Sep 27, 2022
SPE production & operations, May 1, 2022
Day 2 Wed, September 22, 2021, 2021
This study aims to propose an intelligent operational advisory solution that guides the plant ope... more This study aims to propose an intelligent operational advisory solution that guides the plant operation team to optimal HPPT/LPPT pressure settings that compensate for the variation in ambient temperature effect to maximize plant revenue. Traditional industry practice is to operate a gas-oil-separation-plant (GOSP) at fixed operating conditions ignoring the variation in the ambient temperature (Ta) leading to a loss in oil recovery and associated revenue. The variation of ambient temperature (Ta) highly affects the separation process, where ambient temperature varies greatly from summer to winter. To develop a correlation, a GOSP model was constructed by OmegaLand dynamic simulator using a typical Saudi Aramco GOSP design. Oil recovery values were determined by running the process simulation for a typical range of high-pressure production trap (HPPT), low-pressure production trap (LPPT), and ambient temperature (Ta). Then, an intelligent approach was built to determine the optimum p...
Day 3 Wed, February 23, 2022, 2022
The slug flow in the pipes is a common type of flow observed in the oil and gas industries. It ca... more The slug flow in the pipes is a common type of flow observed in the oil and gas industries. It can be observed in the different parts of production systems such as tubing of the vertical or horizontal well, a network of flowlines connecting the wellhead and surface facilities as well as in the pipeline for exports & transportation of the oil and gas to the refineries. The estimation of the pressure drop in the different parts is essential for designing as well as the operation and maintenance of the production system. Among the different flow regimes in the multiphase flow slug flow is always challenging for the oil and gas industry. The wide range of variation in the gas-liquid velocities in two-phase flow makes the flow behavior more complex and difficult to predict especially in the slug flow regime. Further, the increase in viscosity of the liquid slug flow becomes the most common flow pattern in oil and gas pipelines and accurate prediction of slug flow parameters is vital for ...
SPE Production & Operations, 2022
Summary Multiphase flow analysis attracts a lot of attention from researchers from diverse discip... more Summary Multiphase flow analysis attracts a lot of attention from researchers from diverse disciplines. There are several studies including experimental, theoretical modeling, and numerical analysis that were carried out to investigate the multiphase flow. However, many facets of multiphase flow are still unresolved owing to the extremely complex nature of the multiphase flow. The complex interactions of the different phases are leading to different flow regimes that are difficult to predict but essential for developing the computational model. The identification of the flow pattern is still a challenging task. One of the growing fields is the machine learning approach, which can address such complex problems. This study aims to use machine learning to develop models that can identify the flow patterns in multiphase flow. To achieve the objective, a large set of experimental data was collected. The effect of fluid properties, such as density, viscosity, and surface tension, on the f...
All Days, 2018
Two-phase gas/liquid flow in pipes is a common occurrence in the petroleum, chemical, nuclear and... more Two-phase gas/liquid flow in pipes is a common occurrence in the petroleum, chemical, nuclear and geothermal industry. In the petroleum industry, it is encountered in the production, transportation, and processing of hydrocarbon from oil and gas field. In designing these systems, accurate prediction of pressure drop is imperative which is determined from flow regime map. Unfortunately, most of the flow regime maps were developed for the air-water system and widely used for the gas/oil system. In spite of the practical importance the general applicability of these maps is not addressed. In order to improve the generality of flow regime maps it is necessary to evaluate the effect of fluid properties such as surface tension which differ by great magnitude (air/water = 72 dyne/cm and gas/oil = 35 dyne/cm) and viscosity (viscosity of water 1 centipoise and for oil 10 centipoises at standard condition) on the flow regimes. Thus, this study aims to evaluate the effects of surface tension a...
Journal of Petroleum Science and Engineering, 2021
Abstract Two-phase gas/liquid flow in pipes is a common occurrence in the petroleum, chemical, nu... more Abstract Two-phase gas/liquid flow in pipes is a common occurrence in the petroleum, chemical, nuclear and geothermal industry. In the petroleum industry, it is encountered in the production, transportation, and processing of hydrocarbons from the oil and gas fields. In designing these systems, accurate prediction of pressure drop is imperative, which is determined from the flow pattern and flow regime map. Unfortunately, most of the flow regime maps were developed for the air-water system and widely used for the oil/gas system. Despite the practical importance, the general applicability of these maps is not addressed. In order to improve the generality of flow regime maps, it is necessary to evaluate the effect of density, viscosity, and surface tension, which differ by great magnitude on flow regime maps. Thus, this study evaluates the effect of density, viscosity, and surface tension on the flow regime map. To evaluate the effect of fluid properties, experiments were conducted using a horizontal flow loop of 9.15 m (30 ft.) pipe length and 0.0254 m (1-inch) pipe diameter with a two-phase air/liquid system. The surface tension was varied using the surfactant solution, viscosity was varied with the aid of glycerin, and density was varied with the aid of calcium bromide. The superficial velocity of the liquid ranges from 0-3.048 m/sec (0–10 ft/s) and superficial gas velocity ranges from 0-18.288 m/sec (0–60 ft/s) respectively. The experimental data were used to generate a flow pattern map and to predict the effect of these properties on the variation in the boundaries of different flow patterns and pressure drop. The results show that the flow patterns and transition boundaries were affected by fluid properties. The boundary between the annular and slug-annular flow at high velocity, the slug flow and pseudo-slug flow at medium velocity, and inertial wave and ripple wave flow at low velocities are affected by the variation in surface tension, viscosity, and density. The decrease in surface tension shifted the boundary between annular and slug flow toward the left-bottom corner of the flow regime map, while, similar effects were observed due to an increase in viscosity, which is opposite to the effect of surface tension. The increase in density shifts the boundary toward the top-right corner of the flow regime map. The effect of density on the flow pattern transition is significant compared to the viscosity, while the viscosity effect is higher than the surfactant. The effect of fluid properties on pressure drop is noticeable at high velocities, however, the pressure drop is not evident to reveal the flow pattern and boundary transition quantitatively.
Day 1 Mon, May 04, 2020, 2020
Cuttings concentration in annulus that are generated while drilling due to the rate of penetratio... more Cuttings concentration in annulus that are generated while drilling due to the rate of penetration have several problems if it is high and has exceeded the maximum limit. Cuttings accumulation in annulus can lead to hole problems such as lost circulation coincident, stuck pipe incidents, and slow drilling rate which still a difficult challenge once it comes to plan, design and drill wells. If a proper hole cleaning efficiency can be achieved, that ultimately will enable the drilling team to have satisfied well drilling performance. To empower hole-cleaning performance, it must be engineered. In this paper, a new real time model of cuttings concentration in annulus (CCA) enhances drilling performance that will ensure optimized improvement and avoid stuck pipe problems. Knowledge from this paper will help in modeling and monitoring cuttings concentration in annulus while drilling precisely and therefore facilitate improving ROP without jeopardizing the well drilling performance. In ad...
SPE Kingdom of Saudi Arabia Annual Technical Symposium and Exhibition, 2018
Well Inflow Performance Relationship (IPR) has a wide range of applications in both applied and t... more Well Inflow Performance Relationship (IPR) has a wide range of applications in both applied and theoretical sciences, especially in the petroleum production engineering. An accurate prediction of well IPR is very important to determine the optimum production scheme, design production equipment, and artificial lift systems. For these reasons, there is a need for a quick and reliable method for predicting oil well IPR in solution gas drive reservoirs. In this paper, back propagation network (BPN) and fuzzy logic (FL) techniques are used to predict oil well IPR in solution gas drive reservoirs. The models were developed using 207 data points collected from unpublished sources. Statistical analysis was performed to define the more reliable and accurate techniques to predict the IPR. According to the results, the new fuzzy logic well IPR model outperformed the artificial neural networks (ANN) model and the most common empirical correlations. The average absolute error, least standard dev...
SPE Kingdom of Saudi Arabia Annual Technical Symposium and Exhibition, 2018
The Inflow Performance relationship is considered one of the diagnostic tools used by Petroleum e... more The Inflow Performance relationship is considered one of the diagnostic tools used by Petroleum engineers to evaluate the performance of a flowing well. An accurate prediction of well IPR is very important to determine the optimum production scheme, design production equipment, and artificial lift systems. For these reasons, there is a need for a quick and reliable method for predicting the well IPR in gas reservoirs. This study presents back propagation network (BPN) and fuzzy logic (FL) techniques for predicting IPR for a gas reservoir. These models involved 489 data points from published literature papers and conventional PVT reports. Statistical analysis was performed to see which of these methods are more reliable and accurate method for predicting the inflow performance relationship for the gas reservoir. The FL model outperformed the artificial neural network (ANN) model with least average absolute error, least standard deviation and highest correlation coefficient. The propo...
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Papers by Ala'a AL-Dogail