Analyzing Well Production Data Using Combined Type Curve and Decline Curve Analysis Concepts

Abstract

This pa~r was selected for presentabcm by an SPE Prcgram Committee following rev!aw of Imformat!on W"tai"ed M a" abstract $&mifted by tha authm(s) Co"te"ts of the pap,gr, aa presentad, have not baen reviewed by the Swety of Patroleum Engmaers and ara subject to mrrecbon by the author(s) The material, as presented, does not necessarily reflect any poslbon of the Society of Petroleum Engineers, Its offIcars, or membrs Papers presented at SPE meetmgs are sublect to publl=bon rev!aw by Edltorlal Committees of the Smtety of Petroleum Engineers Electromc reproduction, d!stribubon, or storage of any part of this papar for wmmem!al pu~ses w!thl the wrttten wnsant of the Society of Petrolaum Engineers IS prohrbltad Perm!sslon to raprcdum Im print is rastrlcled to an abstract of not more than 300 words. !llustrabons may not be cop!ed The abstract must contain Wnsplcuous nowledgment of where and by whom the pa~r was presented Wr!te L!brarlan, SPE, P O Box 8338w, Rtiardson.~75083-38%, U. S A, fax 01-972.952-9435Abstract This paper presents new production decline curves for analyzing well production data from radial and vertically fractured oil and gas wells, These curves have been developed by combining Decline curve and Type curve analysis concepts to result in a practical tool which we feel can more easily estimate the gas (or oil ) in place as well as to estimate reservoir permeability, skin effect, fracture length and conductivity, etc. Accuracy of this new method has been verified with numerical simulations and the methods have been used to perform analyses using production data from several different kinds of gas wells. Field and simulated examples are included to demonstrate the applicability and versatility of this technology.Decline curve analysis methods, in a variety of forms, have been used in the petroleum industry for more than fifiy years to analyze production data and forecast reserves. Type curve analysis methods have become popular, during the last thirty years, to analyze pressure transient test (e.g. buildup, draw-down) data.result is the development of these new production decline type curves.These new production decline type curves represent an advancement over previous work because a clearer distinction can be made between transient and boundary dominated flow periods.The new curves also contain derivative finctions, similar to those used in the pressure transient literature to aid in the matching process. These production decline curves are, to our knowledge, the first to be published in this format specifically for hydraulically fractured wells of both infinite and finite conductivity. Finally, these new curves have been extended to utilize cumulative production data in addition to commonly used rate decline data.

Integration of microseismic and other post-fracture surveillance with production analysis: A tight gas study

“…Analytical methods that have been developed for production data analysis (PDA) or rate-transient analysis (RTA) (the terms PDA or RTA are used interchangeably in this work) over the past several decades can be categorized as 1. Type-curve methods (pressure-transient analysis analog): Typecurve methods involve the matching of production data (corrected in some cases for variable flowing pressure) to analytical/ empirical solutions of flow equations, cast in dimensionless variable format (Select type-curve references include: Fetkovich, 1980;Fraim and Wattenbarger, 1987;Palacio and Blasingame, 1993;Agarwal et al, 1999;Pratikno and Blasingame, 2003;Ilk et al, 2008a).…”

“…bilinear, linear, elliptical, radial and boundary-dominated flow) is transformed onto specialty plots (using dimensional variables) in such a way that the resulting data trend is linear from which reservoir and stimulation information may be extracted. The straight-line approach has been used by Economides et al (1994), Wattenbarger et al (1998), Poe et al (1999), and Hager and Jones (2001) for analyzing transient flow; the flowing material balance (FMB) method is an example of a straight-line method that is applicable to the boundary-dominated flow regime and may be used to obtain hydrocarbon-in-place estimates (Palacio and Blasingame, 1993;Doublet et al, 1994;Mattar and McNeil, 1997;Agarwal et al, 1999;Mattar and Anderson, 2005). Very recently, a straight-line method was introduced to analyze the elliptical flow regime (Cheng et al, 2009).…”

Unconventional gas reservoir evaluation: What do we have to consider?

“…Type-Curves developed for hydraulically-fractured wells Infinite-and finite-conductivity fractures (ex Pratikno et al, 2003;Agarwal et al, 1999). Elliptical flow (Amini et al, 2007) Example after-closure analysis (ACA).…”

Selected topics in coalbed methane reservoirs

“…Agarwal and Gardner (AG) introduced a different set of type curves (Agarwal et al, 1999) that, while being similar to Blasingame type curves in its application, used a different set of dimensionless variables. The advantage of AG type curves, compared to that of Blasingame, is their ability to illustrate a clear transition from transient flow to boundary-dominated flow.…”