Characteristic Value Method of Well Test Analysis for Horizontal Gas Well

This paper presents a study of characteristic value method of well test analysis for horizontal gas well. Owing to the complicated seepage flow mechanism in horizontal gas well and the difficulty in the analysis of transient pressure test data, this paper establishes the mathematical models of well test analysis for horizontal gas well with different inner and outer boundary conditions. On the basis of obtaining the solutions of the mathematical models, several type curves are plotted with Stehfest inversion algorithm. For gas reservoir with closed outer boundary in vertical direction and infinite outer boundary in horizontal direction, while considering the effect of wellbore storage and skin effect, the pseudopressure behavior of the horizontal gas well can manifest four characteristic periods: pure wellbore storage period, early vertical radial flow period, early linear flow period, and late horizontal pseudoradial flow period. For gas reservoir with closed outer boundary both in vertical and horizontal directions, the pseudopressure behavior of the horizontal gas well adds the pseudosteady state flow period which appears after the boundary response. For gas reservoir with closed outer boundary in vertical direction and constant pressure outer boundary in horizontal direction, the pseudopressure behavior of the horizontal gas well adds the steady state flow period which appears after the boundary response. According to the characteristic lines which are manifested by pseudopressure derivative curve of each flow period, formulas are developed to obtain horizontal permeability, vertical permeability, skin factor, reservoir pressure, and pore volume of the gas reservoir, and thus the characteristic value method of well test analysis for horizontal gas well is established. Finally, the example study verifies that the new method is reliable. Characteristic value method of well test analysis for horizontal gas well makes the well test analysis process more simple and the results more accurate.

Download Full-text

Flow description of gas well in basement granite reservoir from well test analysis

Journal of Physics Conference Series ◽

10.1088/1742-6596/1402/2/022062 ◽

2019 ◽

Vol 1402 ◽

pp. 022062

Author(s):

H K Oetomo ◽

R Sitaresmi ◽

D P Laksana

Keyword(s):

Well Test ◽

Well Test Analysis ◽

Test Analysis ◽

Gas Well

Download Full-text

A New Practical Approach To Evaluate Near Wellbore Formation Damage Parameters Based on Well Test Analysis for Gas Reservoir

10.2118/160867-ms ◽

2012 ◽

Author(s):

Melvin Kome ◽

M.M. Amro ◽

M.M. Hossain

Keyword(s):

Practical Approach ◽

Formation Damage ◽

Well Test ◽

Well Test Analysis ◽

Gas Reservoir ◽

Test Analysis

Download Full-text

Postfracturlng Gas-Well-Test Analysis Using Buildup Type Curves

SPE Formation Evaluation ◽

10.2118/19253-pa ◽

1991 ◽

Vol 6 (03) ◽

pp. 393-400

Author(s):

D.M. Walsh ◽

K.H. Leung

Keyword(s):

Well Test ◽

Well Test Analysis ◽

Test Analysis ◽

Gas Well ◽

Type Curves

Download Full-text

Determination of Average Reservoir Pressure from Pressure Buildup Tests

10.2118/4052-ms ◽

1972 ◽

Author(s):

Hossein Kazemi

Keyword(s):

Reservoir Pressure ◽

Well Test ◽

Well Test Analysis ◽

Test Analysis ◽

Gas Well ◽

Pressure Buildup ◽

Production History ◽

Calculated Average

Abstract Two simple and equivalent procedures are suggested for improving the calculated average reservoir pressure from pressure buildup tests of liquid or gas wells in developed reservoirs. These procedures are particularly useful in gas well test analysis irrespective of gas composition, in reservoirs with pressure-dependent permeability and porosity, and in oil reservoirs where substantial gas saturation has been developed. Long-term production history need not be known. Introduction For analyzing pressure buildup data with constant flowrate before shut in, two plotting procedures are mostly used: The Miller-Dyes-Hutchinson (MDH) plot (1,8) and the Horner plot (2,8). The Miller-Dyes-Hutchinson plot is a plot of pws vs log Δt. The Horner plot consists of plotting the bottom hole shut-in pressure, pws vs log [(tp + Δt)/Δt]. Δt is the shut-in time and tp is a pseudo-production time equal to the ratio of total produced fluid and the last stabilized flowrate prior to shut in. This method was first used by Theis (3) in the water industry.

Download Full-text

Well Test Analysis for a Well in a Constant Pressure Square

10.2118/4054-ms ◽

1972 ◽

Author(s):

Anil Kumar ◽

H. J. Ramey

Keyword(s):

Constant Pressure ◽

Outer Boundary ◽

Initial Pressure ◽

Fluid Injection ◽

Well Test ◽

Well Test Analysis ◽

Test Analysis ◽

Water Influx ◽

Mean Pressure ◽

Well Tests

Abstract Very little information exists for analyzing well tests wherein a part of the drainage boundary is under pressure support from water influx or fluid injection. An idealization is the behavior of a well in the center of a square whose outer boundary remains at constant pressure. A study of this system indicated important differences from the behavior of a well in a closed outer boundary square, the conventional system. At infinite shut in, the constant- pressure boundary case well will reach the initial pressure of the system, rather than a mean pressure resulting from depletion. But it is possible to compute the mean pressure in the constant-pressure case at any time during shut in. Interpretative graphs for analyzing drawdown and buildup pressures are presented and discussed. This case is also of interest in analysis of well tests obtained from developed five-spot fluid injection patterns. Introduction Well-test analysis has become a widely used tool for reservoir engineers in the last twenty years. The initial theory was reported by Horner1 for unsteady flow of single phase fluids of small but constant compressibility to a well producing at a constant rate in -infinite and closed boundary reservoirs. Extension of the theory to the finite reservoir case involves specification of the outer boundary condition. The two most commonly observed conditions are: (1) no flow at the outer boundary corresponding to a closed or depletion reservoir, and (2) constant pressure at the outer boundary corresponding to complete water-drive.

Download Full-text