An electrochemical reactor is an assembly capable of withstanding an electrochemical reaction of practical application. It consists of electrodes surrounded by a volume of liquid electrolyte. Major difficulty and challenge involved in this modeling is the fact that real experimentation with high acid flows is extremely difficult to perform. To overcome them, some assumptions are proposed in order to achieve a computational model suitable to be used as virtual laboratory for redox batteries designers. A model is proposed to analyze the flow of the liquid electrolyte in an electrochemical reactor. Numerical and experimental analyses of such flow in a prototype of a real reactor are proposed. Good hydraulic behaviors will be shown in the majority of the volume, even if there are zones with practically no velocities or with recirculations. These volumes are used to define the parameters that indicate the hydraulic operation. This article describes the experimental and numerical modeling applied to a particular Iron Flow Cell prototype. The experimental validation has shown little numerical errors, smaller than 2.25%. This methodological research provides a very powerful calibrated tool which will help engineers in the future in decisionmaking in order to optimize real designs.
The objective of the work is to identify zones of abnormal pressures and determine the dynamic mechanical properties of the rock in wells without information of sonic and density logs. In the area of study, geomechanical problems have been detected in intermediate hole sections that make it difficult for drilling operations, thus generating non-productive times. Density log (ρb), compressional sonic log (Δtc) and shear sonic log (Δts) are essential to attack this problem and provide possible solutions. To determine the pseudo-sonics logs, it was necessary to modify the correlation of L.Y. Faust (1951), introducing a third variable, the clay volume, it was called Faust Modified Correlation. The pseudo-density log was obtained from the G.H.F. Gardner adjusted correlation (1974). The zones of abnormal pressures were identified by comparing the normal compaction train of the sonic log (Δtcn) with the compressional sonic log (Δtc). And finally the dynamic mechanical properties of the rock were determined such as Poisson's ratio (n), Shear modulus (μ), Bulk modulus (K), Young's modulus (E) and Bulk compressibility (C). The Faust modified correlation showed excellent results of compresional sonic logs, obtaining a correlation coefficient of 93%. The Gardner adjusted correlation as a function of the P wave velocity obtained good results of density logs, with a correlation coefficient of 94%. The zones of abnormal pressures were identified towards the Miocene base with an average pore pressure of 9.17 ppg. In the Pliocene and Miocene high Poisson's ratio was determined that varies between 0.28 and 0.36, and low Young's modulus between 0.85 and 5 Mpsi, this indicates that the rocks are deformed more easily. In the Eocene and Cretaceous, low Poisson's ratio was determined between 0.21 and 0.27, and high Young's modulus between 6.1 and 10 Mpsi, this indicates that the rocks do not easily deform. In addition, the velocity models of the P wave and S wave (VP and VS) were simplified through graphical methods, where VP is a function of the Bulk modulus (K) and Shear modulus (μ), while VS is a function of the Shear modulus (μ). From these models, cubes of Lamé's parameters (λ, μ), elastic properties and S wave velocity were determined using the velocity cube of the RMS compressional wave of seismic as input data to generate cubes of clay volume and fluid saturation with the purpose of looking for opportunities in exploration areas.
Recent development of Bachaquero 2 Field (Lake Maracaibo, Venezuela) has been based mainly on cyclic steam injection on horizontal wells. Initial oil deliverability of the heated wells proved to be up to 5 times greater with respect to the cold wells. This paper presents the results of a multi-disciplinary project focussed on the drilling of a pair of horizontal wells for cyclic stearn injection. The project involved a reservoir characterization and a numerical simulation phase, the drilling, steam injection and production of these wells, a data acquisition project and eventually a fial detailed simulation stage. Experimental and numerical results show that the presence and the thickness of interbedded shale has a severe impact on heat distribution. Very little interference has to be expected between parallel horizontal wells when the separating shale is continuous and its average thickness is greater than about 12 feet. A preliminary stochastic description of the reservoir can be very useful in assessing the presence and expected average thickness of the interbedded shale. The experience allowed us to set the best production strategy for the 2-horizontal well system, in terms of sequence and duration of the cycles, steam rate, total injected steam, steam quality and soak time. It also helped in setting guidelines for the future development of the Bachaquero 2 Field. P. 293
The objective of this paper is to depict the quantification of the production rates of the different phases in deviated wells with high gas-liquid relation using the Flow Array Sensing Tool (FAST). The readings of standard Production Logging Tools (fullbore flowmeter, density, and capacitance) are centralized, therefore they are affected if there is re-circulation of the heavy phase (liquid). The phase segregation and possible apparent down flow of the heavy phase makes it very difficult to determine the distribution of the produced fluids, and in some cases the spinner flowmeter tends to stop or gives inaccurate readings. The cause of these inaccurate readings is that the centralized spinner is affected by positive flow in the high side and negative flow in the low side of the wellbore, and the spinner shows no flow or even apparent downhole flow, when there is a real positive flow. The FAST tool used during the acquisition of the production logs is an ultracompact production logging tool (3 ft long) that is capable to measure multiphase flows with an array of 8 sensors, two in each arm and located 90° apart. These sensors are based on MEMS (Microelectromechanichal Systems), and among the interchangeable sensors we have optical probes that takes ultra-rapid measurements of the refractive index and can determine hold-up of water, oil and gas; the electrical probes that measures conductivity to differentiate hydrocarbons from water, and magnetic probes with micro-spinners to determine the flow rate. Both the three phase optical probes and the electrical probes have excellent response including water hold-ups over 90% that cannot be measured with a standard capacitance tool. The data logged with FAST in deviated wells was processed and interpreted to obtain the apparent flow velocity profiles of each of the 4 micro-spinners and with the three phase optical probes, and the relative bearing curves the velocity maps, and hold-up maps where obtained. The velocity map showed that there was negative flow in the low side of the well and positive flow in the high side while the hold-up map showed the light phase (gas) in the high side of the well. Both maps showed clearly the flow pattern and were used to quantify the production of each perforation and the total rate matched closely the surface rate (within 2% deviation). With the hold-up and velocity maps, the real flow rates were obtained with high confidence, and the flow pattern were shown clearly in deviated wells. The three phase optical probes, and electrical probes are excellent indicators of water and hydrocarbons inflow in a wide range of hold-ups.
Generally, hydrocarbon reserves are determined by the irreducible water saturation using the volumetric equation of the original oil in place (OOIP), regardless of the initial water saturation in the transition zone and as a result overestimate hydrocarbon reserves. The objective of this work is to determine a water saturation model that allows modeling the initial distribution of fluids in the reservoir knowing the original oil-water contact and rock quality. The Leverett J function was used as a variable independent from initial water saturation model; it controls the flow of fluid and depends on the height above the free water level, the interfacial tension, Oil-water fluid density, absolute permeability and effective porosity. In order to define this function, capillary pressure data from oil-water system of drain cycle from special core analysis were used. The core data were modeled and averaged for each rock type with the capillary pressure function from "JNM Jing XD Van Wunnik SCA-9807 (1998)". Then, these curves were converted to values of "J" and these were related with water saturation from capillary pressure curves to obtain functions type SWINIT: f (J). This model gave excellent results in the fluid initial behavior, it means, knowing the original oil-water contact and rock quality, the initial water saturation was quantified in in wells completed in the reservoir. The aforementioned was validated with production / pressure tests. Finally, two sensitivities were performed to calculate OOIP, the first was determined with the irreducible water saturation and the second with the initial water saturation, resulting in a error difference about 5%, in this case, obtaining higher reserves were the calculated with irreducible water saturation. The initial water saturation profile of the wells generated from the model, it is useful to initialize the numerical simulation from reservoir "A", because this model takes as an input data the original oil water contact, which represents the limit reservoir fluid. This model does not depend on the date of drilling wells to determine the initial water saturation of the reservoir.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.