Work With Chemical Additives Advances Understanding of Relative Permeability Shifts

2021 ◽  
Vol 73 (09) ◽  
pp. 37-38
Author(s):  
Chris Carpenter
Keyword(s):  
Steady State ◽  
Relative Permeability ◽  
Flow Rate ◽  
Pressure Difference ◽  
Effective Permeability ◽  
Constant Flow ◽  
Chemical Additives ◽  
Flow Rates ◽  
Steady State Method ◽  
Tight Rocks

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 201520, “Advances in Understanding Relative Permeability Shifts by Imbibition of Surfactant Solutions Into Tight Plugs,” by Mohammad Yousefi, Lin Yuan, and Hassan Dehghanpour, SPE, University of Alberta, prepared for the 2020 SPE Annual Technical Conference and Exhibition, originally scheduled to be held in Denver, Colorado, 5–7 October. The paper has not been peer reviewed. Various chemical additives have been proposed recently to enhance imbibition oil recovery from tight formations during shut-in periods after hydraulic fracturing operations. In the complete paper, the authors develop and apply a laboratory protocol mimicking leakoff, shut-in, and flowback processes to evaluate the effects of fracturing-fluid additives on oil regained permeability. A conventional coreflooding apparatus is modified to measure oil effective permeability (koeff) before and after the surfactant-imbibition experiments. Methodology Proposed Technique for Measuring Oil Effective Permeability. Despite the simplicity of the steady-state method, measuring permeability of tight rocks with this technique is challenging because of its time-consuming nature and the fact that accurate measurement is necessary of extremely low flow rates corresponding to low injectivity of tight rocks. The authors use a pair of plugs from a well drilled in the Montney formation that is a stratigraphic unit of the Lower Triassic age in the western Canadian sedimentary basin located in British Columbia and Alberta. It is mainly a low-permeability siltstone reservoir. In the modified coreflooding apparatus, the authors reduce the effect of compressibility in order to reduce the duration of the transient period by approximately one order of magnitude. Because monitoring changes in pressure is much easier and more accurate than monitoring flow-rate changes, a constant flow-rate mode is used and pressure is recorded with time. Oil is injected at different constant flow rates (qo), and the inlet pressure is monitored. The stable pressure difference across the plug is recorded for each flow rate. After steady-state conditions are reached based on the pressure profile, the qo is increased. This process is repeated until four stable pressure differences corresponding to four different qo are obtained. After the highest qo is reached, it is decreased in similar steps to check the repeatability of each data point. The permeability is calculated with the Darcy equation and slope of the qo vs. stable pressure difference across the plug.

scholarly journals Determination of Permeability and Inertial Coefficients of Sintered Metal Porous Media Using an Isothermal Chamber

2018 ◽  
Vol 8 (9) ◽  
pp. 1670 ◽  
Author(s):  
Wei Zhong ◽  
Xiang Ji ◽  
Chong Li ◽  
Jiwen Fang ◽  
Fanghua Liu
Keyword(s):  
Porous Media ◽  
Steady State ◽  
Flow Rate ◽  
Pressure Difference ◽  
Testing Time ◽  
Sintered Metal ◽  
Steady State Method ◽  
Volume Limit ◽  
Inertial Coefficient

Sintered metal porous media are widely used in a broad range of industrial equipment. Generally, the flow properties in porous media are represented by an incompressible Darcy‒Forchheimer regime. This study uses a modified Forchheimer equation to represent the flow rate characteristics, which are then experimentally and theoretically investigated using a few samples of sintered metal porous media. The traditional steady-state method has a long testing time and considerable air consumption. With this in mind, a discharge method based on an isothermal chamber filled with copper wires is proposed to simultaneously determine the permeability and inertial coefficient. The flow rate discharged from the isothermal chamber is calculated by differentiating the measured pressure, and a paired dataset of pressure difference and flow rate is available. The theoretical representations of pressure difference versus flow rate show good agreement with the steady-state results. Finally, the volume limit of the isothermal chamber is addressed to ensure sufficient accuracy.

Measurement and Correlation of Gas Condensate Relative Permeability by the Steady-State Method

1998 ◽  
Vol 1 (02) ◽  
pp. 134-140 ◽  
Author(s):  
G.D. Henderson ◽  
A. Danesh ◽  
D.H. Tehrani ◽  
S. Al-Shaidi ◽  
J.M. Peden
Keyword(s):  
Steady State ◽  
Relative Permeability ◽  
Flow Rate ◽  
Rate Effect ◽  
Gas Condensate ◽  
Dew Point ◽  
Gas Condensate Reservoirs ◽  
Steady State Method ◽  
Wide Range ◽  
Permeability Rate

Abstract High pressure core flood experiments using gas condensate fluids in long sandstone cores have been conducted. Steady-state relative permeability points were measured over a wide range of condensate to gas ratio's (CGR), with the velocity and interfacial tension (IFT) being varied between tests in order to observe the effect on relative permeability. The experimental procedures ensured that the fluid distribution in the cores was representative of gas condensate reservoirs. Hysteresis between drainage and imbibition during the steady-state measurements was also investigated, as was the repeatability of the data. A relative permeability rate effect for both gas and condensate phases was observed, with the relative permeability of both phases increasing with an increase in flow rate. The relative permeability rate effect was still evident as the IFT increased by an order of magnitude, with the relative permeability of the gas phase reducing more than the condensate phase. The influence of end effects was shown to be negligible at the IFT conditions used in the tests, with the Reynolds number indicating that flow was well within the so called laminar regime at all test conditions. The observed rate effect was contrary to that of the conventional non-Darcy flow where the effective permeability should decrease with increasing flow rate. A generalised correlation between relative permeability, velocity and IFT has been proposed, which should be more appropriate for condensing fluids than the conventional correlation. The results highlight the need for appropriate experimental methods and relative permeability relations where the distribution of the phases are representative of those in gas condensate reservoirs. This study will be particularly applicable to the vicinity of producing wells, where the rate effect on gas relative permeability can significantly affect well productivity. The findings provide previously unreported data on relative permeability and recovery of gas condensate fluids at realistic conditions. Introduction During the production of gas condensate reservoirs, the reservoir pressure will be gradually reduced to below the dew-point, giving rise to retrograde condensation. In the vicinity of producing wells where the rate of pressure reduction is greatest, the increase in the condensate saturation from zero is accompanied by a reduction in relative permeability of gas, due to the loss of pore space available to gas flow. It is the perceived effect of this local condensate accumulation on the near wellbore gas and condensate mobility that is one of the main areas of interest for reservoir engineers. The availability of accurate relative permeability data applicable to flow in the wellbore region impacts the management of gas condensate reservoirs.

scholarly journals A LABORATORY SYSTEM FOR INVESTIGATING OF FLUIDS FLOW CAPACITY THROUGH UNCONSOLIDATED SAND SAMPLES

2020 ◽  
Vol 17 (36) ◽  
pp. 634-645
Author(s):  
Izzat Niazi SULAIMAN ◽  
Yahya Jirjees TAWFEEQ
Keyword(s):  
Porous Media ◽  
Fluid Flow ◽  
Steady State ◽  
Relative Permeability ◽  
Flow Rate ◽  
Pressure Difference ◽  
Absolute Permeability ◽  
Sand Sample ◽  
Flow Capacity ◽  
State Process

Practically all studies of reservoir engineering involve detailed knowledge of fluid flow characteristics. The fluid flow performance in porous media is affected by pressure, flow rate, and volume of single fluid phases. Permeability is a measure of how well a porous media allows the flow of fluids through it. Permeability and porosity form the two significant characteristics of reservoir rocks. This research aimed to present the design of laboratory equipment to test the ability of fluid flow through different sandstone samples. Two sand core samples (coarse sand sample and fine sand sample) were tested. The laboratory findings measurements of porosity, saturation, total permeability, effective permeability, and relative permeability were evaluated. The laboratory tests were performed on partially saturated, unconsolidated core sand for two-phase fluid flow. The experimental work was developed for measuring the flow capacity achieved under the steady-state conditions method. Various grain sizes sands were selected as a porous medium to determine petrophysical properties and fluid flow capacity of the rock sample. Nitrogen and air were utilized as gas-phases, and, for liquid-phases, water was chosen as an injection fluid. The steady-state process method was used to determine the permeability and relative permeability of unconsolidated sands to water flow. Different flow rates were measured for different pressure gradients in a viscose flow. As the flow rate increases, the pressure difference also increased. It can be observed that there are a direct correlation and relationship between the flow rate and the pressure difference. The core plug's absolute permeability was measured using Darcy Equation. Absolute permeability does not depend on fluid characteristics but only on media properties. The sample container contains a more significant amount of sand, decrease the permeability, and therefore requires high pressure for fluid flowing within the sample.

Catheter position and blood gases during constant-flow ventilation

1987 ◽  
Vol 62 (2) ◽  
pp. 513-519 ◽  
Author(s):  
A. S. Slutsky ◽  
A. S. Menon
Keyword(s):  
Steady State ◽  
Flow Rate ◽  
Blood Gases ◽  
Constant Flow ◽  
Arterial Blood Gases ◽  
Catheter Position ◽  
Flow Rates ◽  
Arterial Blood ◽  
Tracheal Carina ◽  
Co2 Elimination

We studied the effect of catheter position and flow rate on gas exchange during constant-flow ventilation (CFV) in eight anesthetized, paralyzed dogs. The distal tips of the insufflation catheters were positioned 0.5, 2.0, 3.5, and 5.0 cm from the tracheal carina. Flow rates were varied between 10 and 55 l/min and steady-state arterial blood gases were measured. At a given flow rate, arterial CO2 pressure (PaCO2) decreased as CFV was administered further into the lung up to a distance of 3.5 cm from the carina; there were no significant differences in PaCO2 at 3.5 and 5.0 cm. For a given catheter position, PaCO2 decreased with increasing flow rate up to a flow rate of 40 l/min. Further increases in flow rate had no significant effect on PaCO2. Arterial O2 pressure (PaO2) was relatively constant at all flow rates and catheter positions. We conclude that, up to a point, CO2 elimination can be improved by positioning the catheters further into the lung; advancing the catheters further than 3.5 cm from the carina may cause over-ventilation of specific lung regions resulting in a relative plateau in CO2 elimination and relatively constant PaO2's. Positioning the catheters further into the lung permits the use of lower flow rates, thus potentially minimizing the risk of barotrauma.

Performance Enhancement by Dynamic Valve Timing of a Multistage Vacuum Micropump

2010 ◽  
Author(s):  
Karthik Kumar ◽  
Luis P. Bernal ◽  
Khalil Najafi
Keyword(s):  
Steady State ◽  
Flow Rate ◽  
Pressure Difference ◽  
Performance Enhancement ◽  
High Vacuum ◽  
Operating Pressure ◽  
Transient Operation ◽  
Valve Timing ◽  
Steady State Operation ◽  
Valve Leakage

This paper presents the results of a theoretical analysis of dynamic valve timing on the performance of a multistage peristaltic vacuum micropump. Prior work has shown that for optimum steady state performance a fixed valve timing which depends on the operating pressure can be found. However, the use of a fixed valve timing could hinder performance for transient operation when the pump is evacuating a fixed volume. At the beginning of the transient the pump operates at low pressure difference and a large flow rate would be desirable. As the pump reaches high vacuum the pressure difference is large and the flow rate is necessarily small. Astle and coworkers1–3 have shown using a reduced order model that for steady state operation short valve open time results in lower inlet pressure and flow-rate and conversely. Here we extend the model of Astle and coworkers to include transient operation, multiple coupled stages and non-ideal leaky valves, and show that dynamic valve timing (DVT) reduces the transient duration by 30% compared to high vacuum pressure valve timing. The results also show a significant reduction in resonant frequency of the pump at low pressures, and quantify the effect of valve leakage.

Study of Unsteady Orifice Flow Characteristics in Hydraulic Oil Lines

1996 ◽  
Vol 118 (4) ◽  
pp. 743-748 ◽  
Author(s):  
Seiichi Washio ◽  
Satoshi Takahashi ◽  
Yonguang Yu ◽  
Satoshi Yamaguchi
Keyword(s):  
Steady State ◽  
Flow Rate ◽  
Pressure Loss ◽  
Flow Characteristics ◽  
High Fidelity ◽  
Flow Rates ◽  
Hydraulic Oil ◽  
Orifice Flow ◽  
Net Pressure ◽  
Clockwise Hysteresis

A technique to measure fluctuating differential pressures with high fidelity has been developed first. When applied to detecting differential pressures generated by an accelerated or decelerated liquid column, the technique turned out to be effective in finding unsteady flow rates. An experimental study has been carried out on periodically changing hydraulic oil flows through an orifice. The results support the validity of the traditional standpoint that characteristics of an unsteady orifice flow can be approximately represented by those of a steady-state one. When inspected in detail, however, a net pressure loss across an orifice in a periodical flow is delayed against a change of the flow rate. The resulting relation between the pressure loss and the flow rate describes a loop with a counter-clockwise hysteresis and a nonlinear twist along the steady-state one. Pressure recovery in a pulsating orifice flow varies with the flow rate almost along the steady-state relation, which is confirmed when the change is not fast.

An Experimental Investigation of High and Low Salinity Waterflood Displacement Under the Steady-State Condition

2021 ◽  
Author(s):  
Abdulla Aljaberi ◽  
Seyed Amir Farzaneh ◽  
Shokoufeh Aghabozorgi ◽  
Mohammad Saeid Ataei ◽  
Mehran Sohrabi
Keyword(s):  
Steady State ◽  
Numerical Simulations ◽  
Relative Permeability ◽  
High Salinity ◽  
Unsteady State ◽  
Dispersion Effect ◽  
Low Salinity ◽  
Steady State Method ◽  
State Method ◽  
Relative Permeability Curves

Abstract Oil recovery by low salinity waterflood is significantly affected by fluid-fluid interaction through the micro-dispersion effect. This interaction influences rock wettability and relative permeability functions. Therefore, to gain a better insight into multiphase flow in porous media and perform numerical simulations, reliable relative permeability data is crucial. Unsteady-state or steady-state displacement methods are commonly used in the laboratory to measure water-oil relative permeability curves of a core sample. Experimentally, the unsteady-state core flood technique is more straightforward and less time-consuming compared to the steady-state method. However, the obtained data is limited to a small saturation range, and the associated uncertainty is not negligible. On the other hand, the steady-state method provides a more accurate dataset of two-phase relative permeability needed in the reservoir simulator for a reliable prediction of the high salinity and low salinity waterflood displacement performance. Considering the limitations of the unsteady state method, steady-state high salinity and low salinity brine experiments waterflood experiments were performed to compare the obtained relative permeability curves. The experiments were performed on a carbonate reservoir sample using a live reservoir crude oil under reservoir conditions. The test was designed so that the production and pressure drop curve covers a wider saturation range and provides enough data for analysis. Consequently, reliable relative permeability functions were obtained, initially, for a better comparison and prediction of the high salinity and the low salinity waterflood injections and then, to quantify the effect of low salinity waterflood under steady-state conditions. The results confirm the difference in relative permeability curves between high salinity and low salinity injections due to the micro-dispersion effect, which caused a decrease in water relative permeability and an increase in the oil relative permeability. These results also proved that low salinity brine can change the rock wettability from oil-wet or mixed-wet to more water-wet conditions. Furthermore, the obtained relative permeability curves extend across a substantial saturation range, making it valuable information required for numerical simulations. To the best of our knowledge, the reported data in this work is a pioneer in quantifying the impact of low salinity waterflood at steady-state conditions using a reservoir crude oil and reservoir rock, which is of utmost importance for the oil and gas industry.

scholarly journals Validating Spray Coverage Rate Using Liquid Mass on a Spray Card

2018 ◽  
Vol 61 (3) ◽  
pp. 887-895
Author(s):  
Michael P. Sama ◽  
Austin M. Weiss ◽  
Emma K. Benedict
Keyword(s):  
Steady State ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Evaporation Rate ◽  
Initial Mass ◽  
Field Validation ◽  
Steady State Method ◽  
State Method ◽  
Coverage Rates

Abstract. Validation of agricultural sprayers is important for quantifying as-applied coverage rates under field conditions. The complexity of modern sprayer control systems presents a challenge for precise field validation due to the use of nozzle control technologies, such as pulse width modulation, to meter chemical flow rates at individual nozzles. Non-uniform flow over time may result in local variations at high spatial resolutions that are ignored when estimating as-applied coverage rates across a field. The purpose of this study was to test several methods for estimating the mass of water applied to a water-sensitive paper spray card target using steady-state and instantaneous measurement techniques. The steady-state method consisted of a spray patternator table used to quantify the mass flow rate distribution across the nozzle width at varying nozzle pressures. The mass flow rate was then projected onto a two-dimensional area traveling across the spray width to calculate the mass of water that was deposited in the area. Two instantaneous sampling methods were used. The first method directly measured the mass of the spray card and water for 5 min after exposure to model the evaporation rate and solve for the initial mass at the time of exposure. The second method indirectly used the percent coverage of the exposed spray card by droplets. Results showed that the error between the calculated mass of water from the mass flow rate and the estimated initial mass of water from the evaporation rate varied between 2% and 8%. The relationships between the calculated and estimated initial mass of water methods and the spray card percent coverage were highly linear (R2 > 0.98). Both instantaneous methods produced results with higher variability between replications than the steady-state method, but the number of replications resulted in acceptably small differences between average mass measurements. These results show the potential for using evaporation rates for laboratory validation and percent coverage for laboratory or field validation of as-applied coverage rates. Keywords: Evaporation rate, Flow measurement, Precision agriculture, Sprayers, Water-sensitive paper.

Investigations in Hydrostatic Planar Bearings Compensated by Tapered-Spool Restrictors I: Flow Rate

2015 ◽  
Vol 32 (1) ◽  
pp. 63-69
Author(s):  
Y. Kang ◽  
H.-C. Cheng ◽  
C.-W. Lee ◽  
S.-Y. Hu
Keyword(s):  
Flow Rate ◽  
Analytical Method ◽  
Pressure Difference ◽  
Load Capacity ◽  
Design Parameters ◽  
Static Characteristics ◽  
Static Stiffness ◽  
Flow Rates ◽  
Single Action ◽  
Hydrostatic Bearing

ABSTRACTThis paper is former part of serial studies to investigate the influence of design parameters of tapered-spool type restrictors on static characteristics of hydrostatic bearing. The flow rates passing restrictors can determine the static characteristics of hydrostatic bearings. In this part an analytical method which includes formulas and solving is utilized to simulate dimensionless flow rate in both single-action and double-action tapered-spool restrictors. The numerical results illustrate the variations of flow rates with respect to the change of pressure and pressure difference, respectively. The findings give that the design parameters of tapered-spool restrictors and the useful range of recess pressure. The following part will depend on this paper results to study load capacity and static stiffness of hydrostatic bearing compensated by tapered-spool restrictor.

scholarly journals EVALUATION OF CAPILLARY END EFFECT IN WATER-OIL PERMEABILITY TESTS USING MULTIPLE FLOW RATES TECHNIQUE

2021 ◽  
Vol 14 (04) ◽  
pp. 259-267
Author(s):  
I. C. A. B. A. Santos ◽  
F. M. Eler ◽  
D. S. S. Nunes ◽  
P. Couto
Keyword(s):  
Relative Permeability ◽  
Flow Rate ◽  
Optimization Problem ◽  
Oil Field ◽  
End Effect ◽  
Flow Rates ◽  
Experimental Procedure ◽  
Injection Methods ◽  
Relative Permeability Curves ◽  
Capillary End Effect

Relative permeability curves obtained in laboratory are used in reservoir simulators to predict production and establish the best strategies for an oil field. Therefore, researchers study several procedures to obtain relative permeability curves. Among these procedures are the multiple flow rates injection methods. Thus, this work proposes to develop an experimental procedure with multiple increasing flows. To make this feasible, simulations were initially carried out at CYDAR, aiming to establish flow rates and time necessary to achieve system stabilization, within the limits of the equipment. After that, tests were carried out establishing the minimum time of 5 hours to stabilize the oil production, and the differential pressure at each flow rate. The accounting and minimization of the capillary end effect in these tests were also evaluated. Capillary pressure constraints contributed to minimize the number of possible solutions to the optimization problem improving the fit of solutions for a specific case.

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