Decline Curve Analysis Using Type Curves--Analysis of Oil Well Production Data Using Material Balance Time: Application to Field Cases

Abstract

This paper_ pI8IllIIIld for pr8S«1lation at1he 1994 PelItlIeum ConIeI1ll1C8 and Exhibition of Mexico held in Veracruz, MEXICO, 1()'13 OclDber 1994. This JllIIl8r _ selected for plllSllnlalion by an SPE P~ram Committee lolowing lllYiew of information oontained in an absllllct submillad by 1he aulhor(s). Contents 011he paper, as preS«lted, haw not been nMewed by 1he Society of Petroleum Engineers and are subjeclto OOll8Ction by the aulho'1s). The ma18riaJ, as presented, does not necessanly reftecl an~position 01 1he Society 01 PlIlrdeum Enslir-rs, its OIlicers, or members. Papers pr8ssnted at SPE meetings are subject to publcalion IIIYiew by Edi1DriaJ Commillees of1he Society of Pelroleum Engineers. Pennission to copy is restriCted to an abstract of not more than 300 words. lUustrations may not be~ed. The absll8cl should contain oonspicuous acknowledgrrient 01 where and by whom 1he paper is p-m-d. Write Ubnuien, SPE, P.O. Box 833836, Richardson. TX75Oll3--3838, U.S.A. Telex, 163245 SPEUT. Harmonic: (b=l) BRIEF SUMMARY This paper presents rigorous methods to analyze and interpret production rate and pressure data from oil wells using type curves to perform decline curve analysis. These methods are shown to yield excellent results for both the variable rate and variable bottomhole pressure cases, without regard to the structure of the reservoir (shape and size), or the reservoir drive mechanisms. Results of these analyses include the following:• Reservoir properties: -Skin factor for near well damage or stimulation, S -Formation permeability, k • In-place fluid volumes:-Original oil-in-place, N -Movable oil at current conditions, N p • mov -Reservoir drainage area, A We have thoroughly verified these analyses and interpretation methods using both synthetic data and numerous field examples. In addition, we provide illustrative examples to demonstrate the ease of analysis and interpretation, as well as to orient the reader as to what are the benefits of rigorous decline curve analysis. INTRODUCTIONThe importance of performing accurate analysis and interpretation of reservoir behavior using only rate and pressure data as a function of time simply can not be overemphasized. In most cases, these will be the only data available in any significant quantity, especially for older wells and marginally economic wells where both the quantity and quality of~types of data are limited. The theoretical application of this technique is for newer wells, at pressures above the bubble point, although we show that the methods described here can be accurately applied at any time during the depletion history of a particular well. The development of modem decline curve analysis began in 1944 when Arpsl published a comprehensive review of previous efforts for the graphical analysis of production decline behavior. In that work, Arps developed a family of functional relations based on the hyperbolic decline model for the analysis of flow rate data.References and illustrations at end of paper Arps' efforts provided a variety of results...

Flow Modeling of Well Test Analysis for Porous–Vuggy Carbonate Reservoirs

“…The standard bi-logarithmic type curves of rate decline analysis (Blasingame et al 1991;Doublet and Blasingame 1994;Marhaendrajana and Blasingame 2001) for q Dd , q Ddi and q Ddi vs. t Dd is similarly obtained.…”

“…(1) A single well production at a constant rate or at a constant wellbore pressure in porousvuggy type carbonate reservoirs; the external boundary of the reservoir may be infinite or closed or at constant pressure for constant rate production; and for constant wellbore pressure production we only consider the closed external boundary (Blasingame et al 1991;Doublet and Blasingame 1994;Marhaendrajana and Blasingame 2001). (2) Total compressibility (rock and fluid) is low and a constant.…”

“…Decline curve dimensionless time of Blasingame (Blasingame et al 1991;Doublet and Blasingame 1994;Marhaendrajana and Blasingame 2001) …”

Characteristic Production Decline Patterns for Shale Gas Wells in Barnett

“…However, a connection to physics has been proved for an exponential decline curve, which represents the solution to the flow equation at constant pressure [18]. This methodology has been widely used for forecasting production or estimating reserves in conventional oil and gas formations [19][20][21][22][23].…”

Predicting emissions from oil and gas operations in the Uinta Basin, Utah

“…Arps (1945) proposed a set of empirically based "decline curve" equations to estimate a well's future production rates based on its rate of decline. Subsequently, the theoretical basis for decline curves has been established by other authors (Doublet et al, 1994;Fetkovich et al, 1996;Shirman, 1998;Ling and He, 2012;Okouma Mangha et al, 2012). Numerous decline curve equations have been developed for specific oil and gas reservoir conditions.…”