An analytical model to predict the effects of suspended solids in injected water on the oil displacement efficiency during waterflooding

Suspended solids in the injection water cause impairment of water injectivity during waterflooding operations. Suspended solids affect reservoir properties and decrease the permeability of reservoir rocks causing an increase of injection pressure and a decrease in water injectivity. Removal of all suspended solids from injection water is an expensive and economically unfeasible process. To minimize the effects of suspended solids to the formation, it is necessary to determine an impairment mechanism of suspended solids on oil displacement and, therefore, optimize the water treatment process. In this paper, an analytical model that describes the relationship between injection water quality and impairment mechanisms on oil displacement is presented. A formation impairment was calculated, introducing the parameter called impairment ratio, which represents the ratio between suspended solids and pore size distribution of reservoir rock. Based on the impairment ratio, decreases in porosity and permeability were calculated with changes in capillary pressure, relative permeability, and displacement efficiency. The model was tested for three different types of injection water. Results indicated the presence of formation impairment even with the smallest particles. Suspended solids had the greatest influence on porosity and permeability impairment. The model could be used as input for reservoir modelling studies for monitoring and controlling displacement efficiency during waterflooding as well as for planning and modification of water treatment units

Harmfulness mapping for the Pechora Sea

Pechora Sea is characterized with many species including birds, fishes, benthic fauna and marine mammals. The food chains in the Pechora Sea ecosystems are simple and vulnerable to contamination even in a small concentration of pollutants. If pollutants harm one type of species, the whole food chain will be affected and can result in reducing a population of the specific species. Arctic climate conditions are characterized with low temperatures that have the influence on dilution, biodegradation and evaporation of contaminants. In this paper, conceptual approach for harmfulness mapping is presented. The main pollution sources in the Pechora Sea were identified associated with possible risk and presented in the risk matrix. Distribution maps of the birds, fishes, benthic fauna and marine mammals were used and embedded to risk maps to determine level of harmfulness for every group. Fuzzy approach was used for qualitative assessment of possible risk events for water, air and soil pollution and its influence on marine environment.acceptedVersio

A NEW MODEL FOR PRODUCED WATER TREATMENT IN ELEMIR OIL FIELD

The oil reservoirs of the southeastern part of the Panonian basin are characterized by considerablepresence of water,i.e.waterdrive. The hydrocarbon reservoirs are mostly in the middle and finalproduction stages. The water production is especially significant in wells producing with an installedElectrical Submersible Pump (ESP). As production continues, it is a realistic expectation that the watercut increases as well.The rapid production of water has affected fluid production in a significantway.Produced water in the Elemir oilfield is gathered, treated and then injected into the porous layersthrough several wells.The current system for the preparation and treatment of produced water in theElemir oilfield has functioned with evident technical issues.The main problems are increased volumesof produced fluids and the deposition of solids (scales) in water treatment system. In thisarticle, a newmodel for produced water treatment is presented, including technical, economic and environmentalaspects. A new model fulfils volumetric requirements, improves oil/water separation and suspendedsolids removal which lead to better injection performance

Applying data mining and artificial intelligence techniques for high precision measuring of the two-phase flow’s characteristics independent of the pipe’s scale layer

Scale formation inside oil and gas pipelines is always one of the main threats to the efficiency of equipment and their depreciation. In this study, an artificial intelligence method method is presented to provide the flow regime and volume percentage of a two-phase flow while considering the presence of scale inside the test pipe. In this non-invasive method, a dual-energy source of barium-133 and cesium-137 isotopes is irradiated, and the photons are absorbed by a detector as they pass through the test pipe on the other side of the pipe. The Monte Carlo N Particle Code (MCNP) simulates the structure and frequency features, such as the amplitudes of the first, second, third, and fourth dominant frequencies, which are extracted from the data recorded by the detector. These features use radial basis function neural network (RBFNN) inputs, where two neural networks are also trained to accurately determine the volume percentage and correctly classify all flow patterns, independent of scale thickness in the pipe. The advantage of the proposed system in this study compared to the conventional systems is that it has a better measuring precision as well as a simpler structure (using one detector instead of two)

Application of neural network and time-domain feature extraction techniques for determining volumetric percentages and the type of two phase flow regimes independent of scale layer thickness

One of the factors that significantly affects the efficiency of oil and gas industry equipment is the scales formed in the pipelines. In this innovative, non-invasive system, the inclusion of a dual-energy gamma source and two sodium iodide detectors was investigated with the help of artificial intelligence to determine the flow pattern and volume percentage in a two-phase flow by considering the thickness of the scale in the tested pipeline. In the proposed structure, a dual-energy gamma source consisting of barium-133 and cesium-137 isotopes emit photons, one detector recorded transmitted photons and a second detector recorded the scattered photons. After simulating the mentioned structure using Monte Carlo N-Particle (MCNP) code, time characteristics named 4th order moment, kurtosis and skewness were extracted from the recorded data of both the transmission detector (TD) and scattering detector (SD). These characteristics were considered as inputs of the multilayer perceptron (MLP) neural network. Two neural networks that were able to determine volume percentages with high accuracy, as well as classify all flow regimes correctly, were trained

Abstracts of The Second Eurasian RISK-2020 Conference and Symposium

This abstract book contains abstracts of the various research ideas presented at The Second Eurasian RISK-2020 Conference and Symposium.The RISK-2020 Conference and Symposium served as a perfect venue for practitioners, engineers, researchers, scientists, managers and decision-makers from all over the world to exchange ideas and technology about the latest innovation developments dealing with risk minimization