Pressure Transient Analysis and Inflow Performance for Horizontal Wells

Abstract

In recent years, pressure transient behavior and inflow performance of horizontal wells have received considerable attention due to the increase in horizontal drilling. In this paper we develop an interpretation methodology for horizontal well pressure transient testing. This methodology is then applied to the interpretation of an actual horizontal well test performed in Prudhoe Bay. The complex geometry associated with horizontal wells makes interpretation of well tests a difficult task. Uniquely determining the system parameters from short time (typical times for vertical well testing) pressure tests is not possible. Combining drawdown and buildup tests, with downhole flowrate measurement is critical for proper interpretation. We also provide a solution for the Inflow Performance of a horizontal well completed in a rectangular drainage volume, where the well can be of arbitrary length and completed at any location within the drainage volume. Introduction Now forward solutions to the diffusivity equation for horizontal well geometry with varied boundary conditions are available in the literature. Moreover, Reiss and Sherrard presented performance and production data from several horizontal wells and mentioned interpretation of well test data. The interpretation of well test data from horizontal wells is a much more difficult task than its vertical counterpart. This difficulty stems from:the main search direction of the parameters usually does not coincide with the depositional environment,the three dimensional nature of the How geometry and lack of radial symmetry, andmore parameters (information) to be obtained. In addition to these difficulties, zonal variation of vertical permeability and shale distribution will make interpretation intricate. A well-defined flow period comparable to that of the infinite acting radial How period (free from storage and boundary effects) of a vertical well is not apparent for horizontal wells. This is largely due to the fact that most horizontal wells will exhibit partial penetration effects, even when they are fully perforated. This fact has already been observed by many authors, and specific methods have been proposed to identify How regimes and their durations under ideal conditions. However, it has not been shown how to extend the identification of How regimes and their usage to the interpretation of real pressure transient tests.

Assessing the Needs to Incorporate Completion Details in a Petroleum Reservoir Simulation Model

“…In addition to Babu & Odeh [10], there are other solutions, like those by Mutalik [12] and Kuchuk [13], that can be applied in determining the pressure drawdown or production rate of a horizontal well.…”

Analytical assessment of horizontal well efficiency with reference to improved oil recovery of the South-East Dragon oil field southern offshore of Vietnam

“…For a horizontal well, there are several solutions available in the literature to calculate the pseudo-steady state productivity such as: Babu and Odeh's method (Babu and Odeh, 1988), Mutalik's method (Mutalik et al, 1988), and Kuchuk's method (Kuchuk et al, 1988). Eqs.…”

“…(6)-(18) were taken from the book Horizontal Well Technology by Joshi (1991). Kuchuk et al (1988) expressed the horizontal well productivity by Eq. (6), using approximate infinite conductivity solution.…”

Recent Advances in Production Engineering

“…At that moment, the three-dimensional (3D) p D is decomposed into a two-dimensional (2D) and a one-dimensional (1D) part, (13) where C H is a "shape" factor, characteristic of well and reservoir configurations in the horizontal plane, and s x is the skin accounting for vertical effects. The expression for this skin effect (46) is (15) which is negligible if the well is placed near the vertical middle of the reservoir.…”