US 6,305,216 B1Granted

Method and apparatus for predicting the fluid characteristics in a well hole

AssigneeProduction Testing Services

InventorBrian H. Samaroo

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Abstract

An improved apparatus and improved method for determining the characteristics of a multi-phase fluid along a well hole having a predefined geometric profile are presented. Various state properties of the fluid, including the temperature, pressure and specific gravity are taken at the wellhead and used as starting values for calculating estimated state properties at various segments along the well hole. Once the state properties are calculated, an estimated mass flow and velocity rate for the fluid and its constituents can be calculated at specific points along the well hole by implementing computer-based programs and algorithms to extrapolate and/or iterate the known parameters and measurements in a progressively incremented manner from the locations of such given starting points at an initial segment up to other further points corresponding to a set of further sequential segments used in the geometric profile mathematical model.

Claims28

Dependent claims

An improved method for determining the characteristics of a fluid along a predefined volume having a geometric profile including a starting point and an ending point, a temperature profile, a starting temperature at said starting point, a starting pressure at said starting point, and a starting total flow rate at said starting point, said method comprising the steps of:

(a) dividing said predefined volume into a series of discrete adjacent segments between said starting point and said ending point said series also including a first segment, a next segment, an incrementally progressing segment and a final segment among a multitude of said discrete segments;
(b) interpolating said temperature profile to determine an estimated temperature at the next segment after said starting point;
(c) interpolating said geometric profile to determine an estimated geometry at said next segment;
(d) using said estimated temperature, said estimated geometry, and said starting total flow rate to calculate an estimated pressure at said next segment;
(e) using said estimated pressure, said estimated temperature, and said estimated geometry to calculate an estimated total flow rate at said next segment;
(f) using said estimated pressure, said estimated temperature, said estimated geometry, and said estimated total flow rate as a starting pressure, a starting temperature, a starting geometry, and a starting total flow rate, respectively, for the incrementally progressing segment subsequent to said next segment;
(g) performing steps (b)-(f) until a next segment that corresponds to the final segment with said ending point is reached;
(h) repeating steps (a) to (g) above to acquire a plurality of sets of characteristics of a fluid along a predetermined volume during, different test periods;
and
(i) performing multiphase flow modeling using said characteristics of a fluid undergoing a flow behavior to determine if a minimum point exists for each set of characteristics of said fluid, thereby determining whether a change in the fluid moving along the predetermined volume occurred.

7 more elements

In a computer device having a display device, an entry device, a storage device, and a processor for executing an evaluation program, said evaluation program capable of reading a geometric profile including a starting point and an ending point of a predefined geometric of a fluid flow volume, a temperature profile, a starting temperature at said starting point, a starting pressure at said starting point, and a starting total flow rate at said starting point, said device further capable of performing the following functions:

(a) dividing said predefined volume into a series of discrete adjacent segments between said starting point and said ending point said series also including a first segment, a next segment, an incrementally progressing segment and a final segment among a multitude of said discrete segments;
(b) interpolating said temperature profile to determine an estimated temperature at the next segment after said starting point;
(c) interpolating said geometric profile to determine an estimated geometry at said next segment;
(d) using said estimated temperature, said estimated geometry, and said starting total flow rate to calculate an estimated pressure at said next segment;
(e) using said estimated pressure, said estimated temperature, and said estimated geometry to calculate an estimated total flow rate at said next segment;
(f) using said estimated pressure, said estimated temperature, said estimated geometry, and said estimated total flow rate as a starting pressure, a starting temperature, a starting geometry, and a starting total flow rate, respectively, for the incrementally progressing segment subsequent to said next segment;
(g) performing steps (b)-(f) a next segment that corresponds to the final segment with until said ending point is reached;
(h) repeating steps (a) to (g) above to acquire a plurality of sets of characteristics of a fluid along a predetermined volume during, different test periods;
and
(i) performing multiphase flow modeling using said characteristics of a fluid undergoing a flow behavior to determine if a minimum point exists for each set of characteristics of said fluid, thereby determining whether a change in the fluid moving along the predetermined volume occurred.

7 more elements

Dependencies are inferred from the claim text.