Analyzing of Drill Stem Test (DST) Result for Dual Porosity Limestone Reservoir

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Zheno Kareem Ahmed Halkawt Ismail Ismail M-Amin

Abstract

The aim of this paper is to discuss and evaluate the result of DST which was conducted in a limestone reservoir of an oil field at the depth interval 3764.29-3903.0 meter in well-1 to evaluate the dynamic characteristics of the reservoirs, for instance: skin effect, permeability, wellbore storage, reservoir boundary and average reservoir pressure. Reservoir Pressure profiles has been recorded for both Buildup and draw down intervals.  Semi-log and log-log coordinates have been used to plot the pressure signature date of both buildup period and its derivative to improve diagnostic and Horner plot. In addition, a dual porosity reservoir and infinite acting characteristic was discovered as a result of the well test data interpretation. Wellbore storage, skin factor and transient flow effects have been detected in the DST analysis on the dual porosity behavior due to phase re distribution.  Using final buildup sections, the flow parameters of dual porosity reservoir were determined as the flow between fissure and matrix was (7.558 x 10-6) while, the storability ratio between fissure and matrix was calculated as 0.3 and permeability is 102 MD for both matrix and the fissure together. However, negative value of skin factor mostly appears in double porosity limestone reservoirs, positive skin factor of the reservoir has been observed in this study. It can be considered that the positive skin factor can be resulted in either the formation was partially penetrated and /or wells were not cleaned up properly.

Keywords

DST, dual porosity, wellbore storage, average reservoir pressure, storability ratio, skin factor.

References

[1] A.C. Gringarten, “Interpretation of Tests in Fissured and Multilayered Reservoirs with Double-Porosity Behavior: Theory and Practice,” J. Pet. Tech., vol. 36 no. 4, pp. 549-564. Apr. 1984.
[2] A.C. Gringarten, “How To Recognize “Double-Porosity” Systems From Well Tests”. J. Pet. Tech., vol. 39 no. 6, pp. 631-633. Jul. 1987.
[3] A. I. Mohammad, A.S.M. Woobaidullah and I. Badrul , “ANALYSIS OF DST TO PREDICT OIL SAND: A CASE STUDY OF KAILASHTILLA FIELD” Bangladesh J. Sci. Res. Vol. 29 no. 1, pp. 19-29 June, 2016.
[4] B. England, “Introduction to well testing”, 1st ed. Venezuela, USA: Shlumberger Wireline and testing, 1998, sec. (3-6).
[5] C. Robert and J. Earlougher: “Advances in Well Test Analysis”. 2ed ed., New York, Dallas, SPE, 1977, Ch. 8, pp. 90-120.
[6] D. Bourdett, “Well test analysis: the use of advanced interpretation”, 1st ed. Paris, France, Elsevier Science B. V., 2002, pp.90-150.
[7] G. Bourdarot, “Well testing Interpretation Methods”, 2ed ed. Paris, France SPE, 1998, pp. 143-170.
[8] H. Cinco, and F. Samaniego, “Transient pressure analysis for fractured wells”, J. Pet. Tech., vol. 33 no. 9, Sep. 1981.
[9] H.J. Ramey Jr: “Advances in Practical Well-Test Analysis”, J. Pet. Tech., vol. 44 no. 6, Jun. 1992.
[10] W. Hurst, “Establishment of the Skin Effect and Its Impediment to Fluid into a Well Bore,” Pet. Eng. pp. 6-16, Oct. 1953.
[11] J. Lee, “Well Testing”. 1st ed. New York, Dallas, SPE, 1982.
[12] J.E. Warren, and P.J. Root, “The Behavior of Naturally Fractured Reservoirs”, J. Pet. Tech. vol. 3 no. 3, pp. 245–255. June. 1963.
[13] K. Serra, A.C. Reynolds, and, R. Raghavan, “New Pressure Transient Analysis Methods for Naturally Fractured Reservoirs” J Pet Techno, vol. 35, no. 12, pp. 2271-2283, May. 1983.
[14] L.G. Jones, and J.W. Watts, “Estimating Skin Effect in a Partially Completed Damaged Well,” J. Pet. Tech. vol. 23 no. 2, pp. 249-252, Feb.1971.
[15] M. Muskat, “Partially Penetrating Wells in Isotropic Formations”, Potential Distribution, Physics, vol. 329 no. 2, pp. 12-20, J. 1932.
[16] O. A. De Swan, “Analytical Solutions for Determining Naturally Fractured Reservoir Properties by Well Testing,” J. Pet. Tech., vol. 16 no. 3, pp. 117–122. Jun, 1976.
[17] R. N. Horne, “Modern well test Analysis (A computer Aided Approach)”, 4th ed. Palo Alto, California: Petro way, Inc, 1990.
[18] W. Marshall Black, “A Review of Drill-Stem Testing Techniques and Analysis”, J. Pet. Tech, vol. 8 no. 6, June 1956.

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