Reservoir management optimization: case study of an oil rim located in the Gulf of Guinea comparing dynamic simulation of low cost smart wells with conventional wells

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MatSWMM - An open-source toolbox for designing real-time control of urban drainage systems

This manuscript describes the MatSWMM toolbox, an open-source Matlab, Python, and LabVIEW-based software package for the analysis and design of real-time control (RTC) strategies in urban drainage systems (UDS). MatSWMM includes control-oriented models of UDS, and the storm water management model (SWMM) of the US Environmental Protection Agency (EPA), as well as systematic-system edition functionalities. Furthermore, MatSWMM is also provided with a population-dynamics-based controller for UDS with three of the fundamental dynamics, i.e., the Smith, projection, and replicator dynamics. The simulation algorithm, and a detailed description of the features of MatSWMM are presented in this manuscript in order to illustrate the capabilities that the tool has for educational and research purposes.Peer ReviewedPostprint (author's final draft

Quick Review: Uncertainty of Optimization Techniques in Petroleum Reservoir Management

The notable increase in petroleum demand, together with a decline in discovery rates, has highlighted the desire for efficient production of existing oil wells worldwide. Mainly, the productivity of the existing large oil fields makes us consider the principles of managing reservoirs to make the most of extraction. At the same time, many different uncertainties in the course of the developing oil field, including geological, operational, and economic uncertainties, have a detrimental impact on the reservoir\u27s effective production, which is why dealing with uncertainty is crucial for maximizing output. There is a broad variety of studies on managing oil reservoirs under uncertainty information in the literature. In this study a short review of earlier works has been done on optimization strategies and management of uncertainty in reservoir production

Two- and three-phase flow functions for numerical simulation of EOR processes

The understanding of governing mechanisms of multi-phase (oil, water, and gas) flow in porous media is of keen interest in petroleum and environmental engineering. In the petroleum engineering context, three-phase flow occurs in several important processes including in enhanced oil recovery (EOR). Recovery of a significant amount of the residual oil in reservoirs after primary recovery and secondary recovery (waterflooding) is important in order to tackle the increasing demand for the energy. EOR methods mainly involve two and three-phase flow in the reservoir. Relative permeability (kr) and capillary pressure (Pc) are two important parameters in multiphase flow which describe the interaction of each fluid in porous media. The importance of these flow functions will be even more significant for three-phase flow systems. This thesis attempts to address three key issues. (i) Improved determination of multi-phase flow functions (kr and Pc). (ii) The impact of parameters affecting flow functions. (iii) Prediction of multi-phase flow functions. Relative permeability (kr) can be measured in the laboratory using steady-state and unsteady-state methods, or estimated by mathematical correlations and pore-network models. As multi-phase flow experiments and in particular steady-state measurements are very time consuming and expensive, more often the unsteady-state method is used for multi-phase kr measurements. In this thesis, a methodology has been devised for calculating kr values and in particular three-phase kr from unsteady-state experiments. The effort was extended to simultaneously calculating Pc from the same coreflood experiment. There are different physical parameters which can affect flow functions. The effect of gas/oil interfacial tension (IFTg/o) on two and three-phase kr and also on residual saturation during alternative water and gas injections has also been studied. Finally, two-phase kr have been estimated for rock and fluid conditions where there is no previous data. This has been achieved by taking data from different conditions under which measurements were made

Developing tools for determination of parameters involved in CO₂ based EOR methods

To mitigate the effects of climate change, CO₂ reduction strategies are suggested to lower anthropogenic emissions of greenhouse gasses owing to the use of fossil fuels. Consequently, the application of CO₂ based enhanced oil recovery methods (EORs) through petroleum reservoirs turn into the hot topic among the oil and gas researchers. This thesis includes two sections. In the first section, we developed deterministic tools for determination of three parameters which are important in CO₂ injection performance including minimum miscible pressure (MMP), equilibrium ratio (Kᵢ), and a swelling factor of oil in the presence of CO₂. For this purposes, we employed two inverse based methods including gene expression programming (GEP), and least square support vector machine (LSSVM). In the second part, we developed an easy-to-use, cheap, and robust data-driven based proxy model to determine the performance of CO₂ based EOR methods. In this section, we have to determine the input parameters and perform sensitivity analysis on them. Next step is designing the simulation runs and determining the performance of CO₂ injection in terms of technical viewpoint (recovery factor, RF). Finally, using the outputs gained from reservoir simulators and applying LSSVM method, we are going to develop the data-driven based proxy model. The proxy model can be considered as an alternative model to determine the efficiency of CO₂ based EOR methods in oil reservoir when the required experimental data are not available or accessible

Dynamic Optimization of Thermodynamically Rigorous Models of Multiphase Flow in Porous Subsurface Oil Reservoirs

In this paper, we consider dynamic optimization of thermal and isothermal oil recovery processes which involve multicomponent three-phase flow in porous media. We present thermodynamically rigorous models of these processes based on 1) conservation of mass and energy, and 2) phase equilibrium. The conservation equations are partial differential equations. The phase equilibrium problems that are relevant to thermal and isothermal models are called the UV and the VT flash, and they are based on the second law of thermodynamics. We formulate these phase equilibrium problems as optimization problems and the phase equilibrium conditions as the corresponding first order optimality conditions. We demonstrate that the thermal and isothermal flow models are in a semi-explicit differential-algebraic form, and we solve the dynamic optimization problems with a previously developed gradient-based algorithm implemented in C/C++. We present numerical examples of optimized thermal and isothermal oil recovery strategies and discuss the computational performance of the dynamic optimization algorithm in these examples.Comment: 20 pages, 6 figure

Streamline Simulation to Improve Polymer Enhanced Oil Recovery for a Mature Oil Field in Austria

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Study and development of robust preformed particle gels for conformance control

To improve the oil recovery of mature reservoirs, technologies referring to conformance control have been widely developed and implemented. Among various technologies, preformed particle gel (PPG) treatment has attracted increasing attentions. PPGs, as a kind of deformable plyometric superabsorbent, could be pumped through injection wells as plugging agents to block the fracture or high-permeability zone in a reservoir. In decade usage of PPGs, an intensively employed material is poly(acrylamide) (PAM) based hydrogel. However, conventional PAM gel did reveal deficient in formidable conditions, such as formations with high temperature and high salinity. Therefore, a novel PPG based on starch-grafting-poly(acrylamide)/nano-composite (SAC) hydrogel has been designed and successfully synthesized. Starch was utilized to improve viscoelasticity thereby facilitate particles\u27 retention in fractures. Nano-clay was introduced to promote not only gel\u27s strength but also its thermal stability. Optimization of components and analysis of environmental sensitivity were conducted via investigating gel swelling ratio and rheological property in which gel\u27s viscoelasticity was quantified through HAAKE Rhescope1 rheometer. Core-flooding tests were performed using fractured sandstone core as physical simulation models to study the plugging performance of SAC gels in fracture media. According to experimental results, SAC gel was turned out an overwhelming PPG material compared with conventional PAM gel --Abstract, page iii

Decision support systems for large dam planning and operation in Africa

Decision support systems/ Dams/ Planning/ Operations/ Social impact/ Environmental effects

A Study on Enhanced Oil Recovery by Surfactants for a Malaysian Sandstone Reservoir

A laboratory scale investigation into the utilization of conventional and nonconventional surfactants for Enhanced Oil Recovery (EOR) was conducted using an inhouse imbibition cell flooded with formation water in the presence of polymers and alkaline mixtures. The success of chemical enhanced recovery treatment hinges on many factors; firstly there is a need for the selected chemical mixture to be sufficiently benign towards the aggressive components of the formation water. Secondly there is a need for the components of the chemical flooding mixture to possess certain desirable properties namely, stability, viscosity, extend of IFT reduction, partition coefficient, adsorption and wettability alteration. Formation water from Angsi field was analyzed for mineral contents using volumetric analyses and Atomic Absorption Spectroscopy (AAS). Surfactants and polymers have been examined for temperature stability using Thermo Gravimetric Analyses (TGA). The viscosities of the polymers have been determined using a rotary viscometer. The presence of alkali, surfactants and a raise in temperature led to a decrease in the viscosity of the polymers. Reduction in IFT at the oil/water interface has been recorded using an interfacial tensiometer. Partition coefficients of the surfactants in oil and water phases have been calculated. Emulsification and wettability alterations have been evaluated by an Atomic Force Microscopy (AFM) and contact angle measurements respectively. BET surface and micropore areas of the cores have been measured. Sandstone cores possessing suitable porosity and permeability have been characterized and used for the imbibition studies. The internal structure and mineral profiles of the sandstones have been illustrated and analyzed using a Scanning Electron Microscopy (SEM) and an Energy Dispersive X-ray (EDX) respectively. Molecular interactions between the various components have been elaborated by Fourier-Transform-Infra red (FTIR) spectroscopy. It was concluded that oil recovery can be significantly enhanced, when an appropriate mixture of non-conventional anionic surfactants (Aerosol OT & TR) has been utilized along with alkali and polymer. The preliminary screening results obtained by an in-house imbibition cell have also been adequately verified by industry accepted coreflooding experiments. Adsorption mechanism of the surfactants on sandstone cores is well elaborated by the Langmuir isotherm instead of the Freundlich isotherm. Adsorption kinetics obeys the Pseudo-second-order kinetics. It can be concluded that the polymer is responsible to increase the macroscopic displacement efficiency, whereas the synergistic effect of the surfactants and alkali are responsible to produce an ultra-low IFT (10" dyne/cm) resulting in a pronounced microscopic displacement efficiency. Nonconventional surfactants can produce an ultra-low IFT even in minuscule amounts of alkali and polymer. It was concluded that Low-Alkaline-Surfactant-Polymer (LASP) is not only an economical technology but it can also enhance oil productiondrastically