Pipe flow experiments of unstable oil-water dispersions with three different oil viscosities: Flow pattern, pressure drop and droplet size measurements

The transport of oil-water dispersions in petroleum production pipelines is difficult to predict and requires special attention since it affects the performance of the entire system. For future field developments it is required to generate accurate predictive models to guarantee an optimal field design. The purpose of this work is to present novel experimental data suitable for improving mechanistic flow models in future works. Oil-water pipe flow experiments were conducted in a stainless-steel flow loop with a L/D ratio of 3766, larger than any comparable setups reported in the literature and sufficient to obtain fully developed flow. A novel level of detail measurements included pressure gradients, density profiles and droplet size distributions. Three oils with different viscosities (oil A: 1.3 cP; oil B: 7 cP; oil C: 22 cP) and brine (3.5 wt% NaCl) as the water phase constituted the three fluid systems used. For each fluid system, several flow rates, and a wide range of water fractions were studied. The fluids were not stabilized by any type of chemical additives. The oil viscosity influences the dispersion behavior, especially for oil continuous flow. For higher oil viscosities the dispersion tends to be more homogeneous, and the pressure drop increases due to increasing wall friction. The droplet size decreases as the oil viscosity increases, presumably due to higher shear stress. Water continuous flows, on the other hand, are less affected by the oil viscosity. A strong drag reduction was found for dispersed flow of all three oils and both oil and water continuous flow. A simple model for the dispersion viscosity and drag reduction was developed based on additional bench scale characterization experiments. With this model the pressure drop could be predicted with good agreement. The data reported in this paper will facilitate the development and validation of mechanistic models for predicting oil-water flows. Previous modelling efforts have been hampered by a lack of detailed measurements, in particular droplet size measurements, hence we believe that this data will allow for significant advancements on the modelling side.publishedVersio

Modelling of dispersed oil/water flow in a near-horizontal pipe

A gravity-diffusion model was implemented for predicting water concentration profiles in dispersed oil-continuous oil–water flows. In this model, the measured droplet size distributions were used instead of a droplet size closure law. The turbulent diffusion was modelled assuming single-phase flow while the gravitational drift was based on closure laws from the literature, including hindrance effects. The results showed that including the effect of turbulence on the drag force was important, where the turbulent fluctuations cause an increase in the average drag because of the non-linearity of the drag law. The model yielded a good match with the experimental data reported by Gonzales et al. (Gonzalez et al., 2022), especially at the highest flow rates. We also concluded that the following model simplification could be introduced without changing the results significantly: 1) The droplet size distributions could be replaced by the Sauter mean droplet size. 2) The diffusivity profile model could be replaced by a uniform diffusivity model.publishedVersio

Decision support method for early-phase design of offshore hydrocarbon fields using model-based optimization

This paper presents the development of a method to provide decision support in the feasibility studies and concept planning phases of oil and gas field development. The objective in developing the methodology was to provide an easy-to-use facility to integrate the production-governing elements of oil and gas fields that capture the integrated production and economic performance of the system. This in a modular and scalable manner that includes numerical optimization and uncertainty analyses needed to support engineering decisions The method follows a series of steps that allow determining the optimal field production profile, drilling schedule, type of offshore structure, pressure support method and selection of artificial lift. The first step consists of creating efficient (low running time) proxy models of the production performance of the field and the costs figures associated to the project. The proxy model of the production performance is based on curves of maximum production rates versus cumulative production, and contains all relevant field design features and computation of the most relevant performance indicators to consider in the evaluation. The proxy model to estimate the costs associated to the project are based on linear equations function of production rates and number of wells. The second step is to perform numerical optimization to find optimal production profile and drilling schedule that maximize the net present value of the specific development strategies considered. For the last step, an evaluation of the effect of uncertainties on the results of the numerical optimization using probabilistic methods is performed. The method was applied in a synthetic production system based on public data of Wisting field (currently under development). The field is a remote low energy oil reservoir located in the Barents Sea. Nine (9) strategies, obtained from the combination of three recovery support methods and three processing facilities, were compared using the net present value as decision factor. The best strategy consists of using a Tension Leg Platform as processing facility and multiphase boosting plus water injection as recovery support method. This strategy generated the highest production and required the lowest costs, resulting in the highest profitability. It was demonstrated that the methodology successfully finds optimal field design features while quantifying the effect of uncertainties

Pipe flow experiments of unstable oil-water dispersions with three different oil viscosities: Flow pattern, pressure drop and droplet size measurements

The transport of oil-water dispersions in petroleum production pipelines is difficult to predict and requires special attention since it affects the performance of the entire system. For future field developments it is required to generate accurate predictive models to guarantee an optimal field design. The purpose of this work is to present novel experimental data suitable for improving mechanistic flow models in future works. Oil-water pipe flow experiments were conducted in a stainless-steel flow loop with a L/D ratio of 3766, larger than any comparable setups reported in the literature and sufficient to obtain fully developed flow. A novel level of detail measurements included pressure gradients, density profiles and droplet size distributions. Three oils with different viscosities (oil A: 1.3 cP; oil B: 7 cP; oil C: 22 cP) and brine (3.5 wt% NaCl) as the water phase constituted the three fluid systems used. For each fluid system, several flow rates, and a wide range of water fractions were studied. The fluids were not stabilized by any type of chemical additives. The oil viscosity influences the dispersion behavior, especially for oil continuous flow. For higher oil viscosities the dispersion tends to be more homogeneous, and the pressure drop increases due to increasing wall friction. The droplet size decreases as the oil viscosity increases, presumably due to higher shear stress. Water continuous flows, on the other hand, are less affected by the oil viscosity. A strong drag reduction was found for dispersed flow of all three oils and both oil and water continuous flow. A simple model for the dispersion viscosity and drag reduction was developed based on additional bench scale characterization experiments. With this model the pressure drop could be predicted with good agreement. The data reported in this paper will facilitate the development and validation of mechanistic models for predicting oil-water flows. Previous modelling efforts have been hampered by a lack of detailed measurements, in particular droplet size measurements, hence we believe that this data will allow for significant advancements on the modelling side

Modelling of dispersed oil/water flow in a near-horizontal pipe

A gravity-diffusion model was implemented for predicting water concentration profiles in dispersed oil-continuous oil–water flows. In this model, the measured droplet size distributions were used instead of a droplet size closure law. The turbulent diffusion was modelled assuming single-phase flow while the gravitational drift was based on closure laws from the literature, including hindrance effects. The results showed that including the effect of turbulence on the drag force was important, where the turbulent fluctuations cause an increase in the average drag because of the non-linearity of the drag law. The model yielded a good match with the experimental data reported by Gonzales et al. (Gonzalez et al., 2022), especially at the highest flow rates. We also concluded that the following model simplification could be introduced without changing the results significantly: 1) The droplet size distributions could be replaced by the Sauter mean droplet size. 2) The diffusivity profile model could be replaced by a uniform diffusivity model

Modelling of dispersed oil/water flow in a near-horizontal pipe

A gravity-diffusion model was implemented for predicting water concentration profiles in dispersed oil-continuous oil–water flows. In this model, the measured droplet size distributions were used instead of a droplet size closure law. The turbulent diffusion was modelled assuming single-phase flow while the gravitational drift was based on closure laws from the literature, including hindrance effects. The results showed that including the effect of turbulence on the drag force was important, where the turbulent fluctuations cause an increase in the average drag because of the non-linearity of the drag law. The model yielded a good match with the experimental data reported by Gonzales et al. (Gonzalez et al., 2022), especially at the highest flow rates. We also concluded that the following model simplification could be introduced without changing the results significantly: 1) The droplet size distributions could be replaced by the Sauter mean droplet size. 2) The diffusivity profile model could be replaced by a uniform diffusivity model

Cambios en medidad antropométricas, capacidad aerobica y calidad de vida a través del ejercicio en personas obesas de una institución de III nivel del suroccidente colombiano

La obesidad es definida por la Organización Mundial de la Salud (OMS) como una acumulación anormal o excesiva de grasa que puede ser perjudicial para la salud, su origen se debe a diferentes características entre ellos la edad, la raza, la genética, estilos de vida, el status social y el grado de educación, entre otros; se ha convertido en un problema de salud pública en los últimos años, de prevalencia creciente que junto con el sobrepeso, afecta más de la mitad de la población en los países desarrollados, por lo que ha sido considerada por la International Obesity Task Force (IOTF) y OMS como la epidemia del siglo XXI. El objetivo del estudio fue determinar los cambios en medidas antropométricas (IMC, pliegues cutáneos y perímetro abdominal), capacidad aeróbica y calidad de vida en personas obesas que participen de un programa de acondicionamiento físico por 12 semanas en una institución de salud de III nivel del sur occidente colombiano. Para dicha finalidad se utilizaron instrumentos como balanza, tallimetro, cinta métrica, adipometro, test de caminata 6 minutos (TC6M) y el cuestionario de calidad de vida Sf-36. Es un estudio de serie de casos con análisis pre y post-ntervención y con muestreo por conveniencia. La población estuvo constituida por dos mujeres obesas de 47 y 53 años de un Hospital de III Nivel del Suroccidente Colombiano. Se logró identificar que la intervención con 12 semanas de ejercicio dirigido tuvo un impacto positivo referente a las medidas antropométricas (peso, IMC, PA, pliegues cutáneos) para los dos sujetos de intervención, con cambios más notables en los pliegues cutáneos; Ambos sujetos presentaron aumento en la distancia recorrida en el test de caminata, 43,73 m para el sujeto No. 1 y de 11,6 m para el sujeto No. 2 luego de las 12 semanas de acondicionamiento físico; En calidad de vida ambos participantes mejoraron para cada componente de salud física y salud mental; el sujeto No. 1 presento mayor porcentaje de cambio en el rol físico y vitalidad; y para el sujeto No. 2, fue en rol emocional y función social.PregradoFISIOTERAPEUT