What is infinite acting radial flow?
What is infinite acting radial flow?
Infinite-acting radial flow (IARF) is the main flow regime of interest, occurring after the early wellbore-dominated response but before any boundary responses are seen in late time.
What is radial flow in reservoir?
Radial flow. The model assumes cylindrical flow in the reservoir where flow across the formation is horizontal and fluid moves radially toward the wellbore.
What is radial flow of oil and gas?
Flow into the wellbore during a well test, from a reservoir with no apparent outer boundary limit affecting fluid flow during the test period, the direction of flow being perpendicular to the axis of the well.
What is spherical flow?
1. n. [Well Testing] A flow regime that occurs when the predominant flow pattern in the reservoir is toward a point. Spherical flow occurs for partial penetration and limited-entry completions. This flow regime is recognized as a -1/2 slope in the pressure derivative on the log-log diagnostic plot.
What is meant by infinite acting reservoir?
1. n. [Well Testing] A reservoir with no apparent outer boundary limit affecting fluid flow during a test period. Unless an outer boundary, such as a nearby fault, is close to the wellbore, it usually takes a day or more for outer boundaries to affect well-test results.
What is wellbore storage?
Wellbore storage is a function of the wellbore fluid and the completion size. The wellbore storage coefficient is defined as: C = Cf Vf with Cf the fluid compressibility and Vf the fluid volume. It is measured in units of bbl/psi.
What does radial flow mean?
: having the working fluid flowing mainly along the radii of rotation a radial-flow turbine — compare axial-flow.
What is the difference between axial-flow and radial flow?
“Axial” refers to the direction of flow produced by the impeller. Similar to the axial flow turbine, the term “radial” describes the flow of liquid resulting from the impeller. The radial turbine blades are welded to the hub with the blade surfaces parallel to the shaft.
What is the difference between axial flow and radial flow?
What is steady radial flow?
The flow towards a well is termed radial flow. The hydraulic gradient of the cone of depression causes water to flow at a constant rate from the recharge boundary to the well. Such a hydraulic condition in the aquifer is known as a steady flow condition.
What is radial flow?
What is a Horner plot?
A type of build up pressure test plot. The Horner plot uses a recording of the pressure during pressure build-up to predict its virgin reservoir pressure. The slope (m) of the extrapolated line reflects the nature of the reservoir rock and the fluids flowing through the rock.
How are infinite acting radial flow equations derived?
The procedure is based on new infinite-acting-radial-flow equations that apply for all inclination angles of the wellbore in a single-layer, 3D anisotropic, homogeneous porous medium. The equations for 2D anisotropic cases are also presented and are derived from the general equations given for the 3D anisotropic case.
Why is IARF referred to as infinite acting?
As IARF occurs before the effects of boundaries, the response during this time behaves as if the reservoir is infinite; hence, the term infinite acting (Horne, 1995). During IARF the reservoir is effectively a flat circular disc, with horizontal flow pathways converging on the well equally from all directions.
How is the early transition of radial flow described?
The early transition is described by β′ derivative curves. As on the pressure type-curve of Fig. 4.16, the derivative β′ curves are obtained by displacing derivative CDe2S curves by a factor of two along the pressure and time axes. During transition, the 0.5 line plateau of the CDe2S curves is replaced by a constant derivative 0.25 line.
Is the diffusivity of an infinite acting reservoir dimensionless?
Assuming an infinite-acting reservoir with constant pressure at the wellbore, we have the following early time approximation for the diffusivity equation in dimensionless form: For radial flow (low pressure approximation) in a vertical well: