Concerning the Calculation of Inflow Performance of Wells Producing from Solution Gas Drive Reservoirs

Abstract

Estimating probable flow rates of wells producing from solution gas drive reservoirs is a problem frequently encountered by petroleum engineers. One approach to an answer involves the simultaneous solution of the well's inflow performance relationship (IPR) and the rate-dependent pressure losses in the well tubing, surface flow lines, and chokes. Nind covers very nicely several graphical methods of accomplishing the simultaneous solution. This note presents relationships that can be used to obtain IPR presents relationships that can be used to obtain IPR curves applicable to bounded solution gas drive reservoirs in which the average reservoir pressure is less than the reservoir fluid bubble-point pressure. Vogel's dimensionless IPR equation is the basis for the development. An example illustrates how future IPR curves can be developed from a current productivity index value. Vogel developed a general dimensionless relationship for wells producing under conditions outlined above and under pseudosteady-state conditions given by Eq. 1. (1) = 1 - 0 .2 - 0 .8 , where qo = stock-tank oil producing rate, B/D pwf = wellbore flowing pressure, psi pwf = wellbore flowing pressure, psip = average reservoir pressure, psi p = average reservoir pressure, psi qo max = maximum rate the well would producefor conditions of pwf = 0. Eq. 1 can be rearranged to = ...............(2) The productivity index of a well is defined by (3) J = Substitution of Eq. 3 into Eq. 2 yields (4) J = Physical conditions inherent in Eq. 4 are that reservoir Physical conditions inherent in Eq. 4 are that reservoir gas and oil saturations, as well as reservoir pressure, vary with distance away from the wellbore, and that the well's skin factor is zero. Let us now consider the situation in which fluid saturations are the same everywhere in the reservoir. This is analogous to a "zero drawdown" situation. Let J* be the well's productivity index under these conditions. Mathematically, (5) lim J J* = Applying the limit conditions to Eq. 4 yields (6) J* = P. 1141

Modeling Inflow Performance Relationships for Wells Producing From Two-Layer Solution-Gas Drive Reservoirs Without Cross-Flow

“…Many equations have been presented in the literature to determine the future performance of wells producing from homogeneous solution gas-drive reservoirs (Levine and Prats, 1961;Standing, 1971;Fetkovich, 1973;Camacho-V and Raghavan, 1989). None of the published studies proposed an equation for two-layer solution gas-drive reservoirs.…”

“…Thus, to accurately capture future well performance, IPR equations should integrate the effects of reservoir depletion. Standing (1971), Fetkovich (1973), Al-Saadoon (1980), Kelkar and Cox (1985), Klins and Clark (1993), and Poe et al (1995) presented techniques for estimating future IPR. Furthermore, most mature solution-gas drive reservoirs produce water as a third phase beside oil and gas, which dictates developing IPR formulation capable of predicting three-phase fluid flow behavior (Chu and Evans, 1983;Wiggins et al, 1992;Wiggins, 1994).…”

An Integrated Horizontal- and Vertical-Flow Simulation With Application to Wax Precipitation

“…and did not take Into account rock damage zone due to drilling. Standing (1971). Dias·Couto and Golan (1982).…”

A Novel Method to Predict the Well Inflow Performance Relationships Curves By Artificial Intelligence Techniques

“…Zambrano (2002) used a neural network model to predict dew point pressure for retrograde gases which is illustrated that the provided model was better estimation techniques for the existed correlations [2]. Incompatible results state again by Camacho and Raghavan; it was noted that the predicted IPR by Vogel indicates the definition of flow efficiency should also represent quadratic forms of the depression equation rather than the definition of the righthand side of the reflection [3][4][5]. Furthermore, they concentrated on the utilization of a numerical simulation to investigate the effect of the skin on the well production by solution gas drive.…”