The Application of Buckley-Leverett Displacement to Waterflooding in Non-Communicating Stratified Reservoirs

El-Khatib, Noaman

doi:10.2118/68076-ms

Cited by 19 publications

(13 citation statements)

References 10 publications

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“…The injectivity ratio starts at a value of unity and ends at a value of M(1 -N G ) for the noncommunicating cases, as discussed previously. For the communicating case, however, the injectivity ratio ends at the value of M/(1 þ MN G ) (El-Khatib 2001). For the case of M ¼ 2.0, the injectivity ratio increases from 1.0 to 1.5 for the noncommunicating case and to 4/3 for the communicating case.…”

Section: Development Of the Model Equationsmentioning

confidence: 95%

“…El-Khatib (1985) compared the performance of communicating and noncommunicating systems to investigate the effect of communication on waterflooding performance, and he derived expressions for the injectivity ratios for both communicating and noncommunicating systems. El-Khatib (2001) applied the Buckley-Leverett frontal-advance theory to noncommunicating stratified reservoirs, allowing for a saturation gradient behind the displacement front.…”

Section: Introductionmentioning

confidence: 99%

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The Modification of the Dykstra-Parsons Method for Inclined Stratified Reservoirs

El-Khatib

2012

SPE Journal

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The Dykstra-Parsons method (Dykstra and Parsons 1950) is used to predict the performance of waterflooding in noncommunicating stratified reservoirs. Much interest has been shown recently in the application of the method to chemical flooding, particularly for the case of polymer injection used for mobility control. The original method assumes that the reservoir layers are horizontal; however, most oil reservoirs exhibit a dip angle, with water being injected in the updip direction. Therefore, it is important to account for the effect of inclination on the performance of the method.A modification of the Dykstra-Parsons equations is obtained to account for reservoir inclination. The developed model includes a dimensionless gravity number that accounts for the effect of the dip angle and the density difference between the displacing and displaced fluids. The derived equation that governs the relative locations of the displacement fronts in different layers is nonlinear, includes a logarithmic term, and requires an iterative numerical solution. This solution is used to estimate the fractional oil recovery, the water cut, the injected pore volume, and the injectivity ratio at the time of water breakthrough in successive layers.Solutions for stratified systems with log-normal permeability distribution were obtained and compared with horizontal systems. The effects of the gravity number, the mobility ratio, and the Dykstra-Parsons permeability-variation coefficient (V DP ) on the performance were investigated. Cases of updip and downdip injection are discussed.It was found that for a positive gravity number (updip water injection), performance is enhanced in terms of delayed water breakthrough, increased fractional oil recovery, and decreased water cut as compared with horizontal layers. This occurs for both favorable and unfavorable mobility ratios but is more evident in unfavorable mobility ratios and more-heterogeneous cases. For the case of a negative gravity number (downdip water injection or updip gas injection), the opposite behavior was observed.The results were also compared with the performance of inclined communicating reservoirs with complete crossflow. The effect of communication between layers was found to improve fractional oil recovery for favorable and unit mobility ratios and decrease recovery for unfavorable mobility ratio.

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Section: Development Of the Model Equationsmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

The Modification of the Dykstra-Parsons Method for Inclined Stratified Reservoirs

El-Khatib

2012

SPE Journal

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“…In the idealized pattern model, which is not dissimilar in concept to the model presented by [12], the layers are assumed to be non-communicating and the influence of gravity and capillarity is neglected. All layers are assigned the same overall average porosity and initial oil saturation as the block, while the permeability contrast between layers is captured through the average Dykstra-Parsons coefficient, calculated as an ensemble average over all wells in the block.…”

Section: Waterflood Efficiency Typecurvesmentioning

confidence: 99%

Advanced Data-Driven Performance Analysis For Mature Waterfloods

Mijnarends¹,

Frolov²,

Grishko³

et al. 2015

SPE Annual Technical Conference and Exhibition

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We present a novel, data-driven approach to integrated well/reservoir performance analysis and opportunity identification for mid-to late-life pattern waterfloods.The Salym group of oilfields is located onshore in Western Siberia, Russia's prime oil producing province, and is operated by Salym Petroleum Development (SPD), a 50-50 joint venture between Shell and Gazprom Neft. The main productive formation, comprising strongly layered, deltaic/fluviatile sandstones, has been developed as a pattern waterflood, with over 950 deviated wells drilled since 2004. Overall watercut is currently around 82% and with oil production declining at 6-7% year on year, waterflood management is an absolute strategic priority.The operator has responded to this challenge by investing heavily in waterflood management and performance evaluation. Particularly, a dedicated effort was made to develop the company's enterprise information architecture and create a purpose-built online waterflood management tool (WMT). All Salym geological, completion, production and well status data is automatically quality-checked, stored and updated in an integrated waterflood database and made accessible through the WMT. The WMT provides a wide range of functionality for data visualization, performance diagnostics and analysis. Furthermore, it is coupled to a full-field surveillance simulation model, which auto-updates with new oilfield data as it becomes available and outputs streamlines, well allocation factors, maps of remaining oil distribution and pattern-and block-level calculated properties.These technologies have enabled the development and implementation of a structured methodology for waterflood performance evaluation that involves systematic assessment of blocks of 20-50 wells in the form of an Annual Field Review (AFR) followed by a series of deep-dive Integrated Block Reviews (IBRs). During the AFR, each block is assessed against a set of KPIs and scored and prioritised in terms of its health status and projected recovery shortfall. Based on this prioritisation, blocks are scheduled for review in an IBR during the course of the year. The IBRs focus on individual wells, patterns and reservoirs and during the reviews concrete well, reservoir and facilities management (WRFM) opportunities are identified to address performance gaps and sweep or accelerate remaining oil. These opportunities are captured in an online opportunity register coupled to an online database for workover strategy preparation.The framework of technologies and processes presented in this paper was instrumental in planning and executing over 260 WRFM activities (not including simple pump change-outs) across the Salym fields in 2014, delivering in excess of 3.2 Mln bbls of in-year oil production.

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“…Tian et al [26] studied the influence of strata pinch out and lens on vertical interlayer interference tests by establishing a three-layer model. Using the theory of B-L displacement mathematical model, Noaman et al [27][28][29] analyzed the influence of gravity number, mobility ratio, permeability variation coefficient and liquidity on waterflooding performance in inclined multilayer reservoirs, and compared the finding with the D-P method. Guo [30] established the low permeability gas reservoir model for multilayer commingling production, considering the Darcy flow and the starting pressure gradient in both cases.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Vertical Producing Degree of Commingled Production via Waterflooding for Multilayer Offshore Heavy Oil Reservoirs

Shen

Cheng

Sun³

et al. 2018

Energies

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Recently, commingling production has been widely used for the development of offshore heavy oil reservoirs with multilayers. However, the differences between layers in terms of reservoir physical properties, oil properties and pressure have always resulted in interlayer interference, which makes it more difficult to evaluate the producing degree of commingled production. Based on the Buckley–Leverett theory, this paper presents two theoretical models, a one-dimensional linear flow model and a planar radial flow model, for water-flooded multilayer reservoirs. Through the models, this paper establishes a dynamic method to evaluate seepage resistance, sweep efficiency and recovery percent and then conducts an analysis with field data. The result indicates the following: (1) the dynamic difference in seepage resistance is an important form of interlayer interference during the commingled production of an offshore multilayer reservoir; (2) the difference between commingled production and separated production is small within a certain range of permeability ratio or viscosity ratio, but separated production should be adopted when the ratio exceeds a certain value.

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The Application of Buckley-Leverett Displacement to Waterflooding in Non-Communicating Stratified Reservoirs

Cited by 19 publications

References 10 publications

The Modification of the Dykstra-Parsons Method for Inclined Stratified Reservoirs

The Modification of the Dykstra-Parsons Method for Inclined Stratified Reservoirs

Advanced Data-Driven Performance Analysis For Mature Waterfloods

Evaluation of the Vertical Producing Degree of Commingled Production via Waterflooding for Multilayer Offshore Heavy Oil Reservoirs

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