Pressure Transient Behavior of a Finite-Conductivity Fractured Well With Spatially Varying Fracture Properties

1992 ◽  
Author(s):  
B.D. Poe ◽  
P.C. Shah ◽  
J.L. Elbel
Keyword(s):  
Transient Behavior ◽  
Finite Conductivity ◽  
Pressure Transient ◽  
Fracture Properties ◽  
Fractured Well ◽  
Spatially Varying

Pressure transient behavior of a fractured well in multi-region composite reservoirs

2017 ◽  
Vol 158 ◽  
pp. 535-553 ◽  
Author(s):  
Qi Deng ◽  
Ren-Shi Nie ◽  
Yong-Lu Jia ◽  
Quan Guo ◽  
Kai-Jun Jiang ◽  
...  
Keyword(s):  
Transient Behavior ◽  
Pressure Transient ◽  
Fractured Well

Influence of Fracture Heterogeneity and Wing Length on the Response of Vertically Fractured Wells

1983 ◽  
Vol 23 (02) ◽  
pp. 219-230 ◽  
Author(s):  
C.O. Bennett ◽  
N.D. Rosato ◽  
A.C. Reynolds ◽  
R. Raghavan
Keyword(s):  
Wing Length ◽  
Constant Width ◽  
Transient Behavior ◽  
Pressure Response ◽  
Finite Conductivity ◽  
Time Data ◽  
Fracture Conductivity ◽  
General Terms ◽  
Damaged Zone ◽  
Fractured Well

Abstract A finite-conductivity vertical fracture intersecting a well produced at a constant rate or at a constant pressure is considered. The pressure (or rate) response is obtained from a numerical model. Two aspects of this problem are considered:variable fracture conductivity andunequal fracture wing lengths. The first part of this paper examines the influence of fracture conductivity on the well response. In practice, the fracture conductivity is a decreasing function of distance from the wellbore. If the fracture conductivity decreases monotonically with distance from the wellbore, then at late times the variable fracture conductivity solutions behave like a constant-conductivity fracture, with conductivity equal to the arithmetic average of the conductivity. At early times the response is identical to that of a constant-conductivity fracture, corresponding to the highest conductivity of the fracture. For the variable fracture conductivity case, the bilinear flow period characterized by a one-quarter slope line may be obscured. Thus, analysis of short-time data can be difficult. We also consider situations where the fracture conductivity does not decrease monotonically with distance. The response for these cases is discussed in detail. The second part of the paper examines the effect of unequal wing lengths on the pressure response. We delineate conditions under which the effect of wing length on the response will become dominant. We discuss the influence of wing length on both early- and long-time data. Introduction To our knowledge no quantitative information is available in the literature regarding the effect of nonuniform fracture conductivity on the transient behavior of a fractured well. (In this work, nonuniform or variable fracture conductivity refers to the situation where the fracture conductivity is a function of distance from the wellbore.) The fracture is usually considered to be of constant width and constant permeability. However, in virtually all situations, fractures are designed such that the fracture conductivity is not uniform. The principal thrust of the first part of this paper concerns the influence of nonuniform (variable) fracture conductivity on the transient behavior of the well. We evaluate the consequences of neglecting variations in fracture conductivity when constant (uniform) conductivity solutions are used to determine the fracture half-length. We found that the effect of variable conductivity on well performance could be quantified in general terms if the conductivity decreases uniformly from the wellbore to the tip of the fracture. The behavior of a fractured well that is plugged is examined. The effect of a damaged zone (within the fracture) adjacent to the wellbore is also examined. Virtually all studies on transient pressure response assume that the well is located at the center of the fracture-i.e., the fracture wing lengths are equal. SPEJ P. 219^

Pressure-Transient Behavior of Partially Penetrating Inclined Fractures With a Finite Conductivity

SPE Journal ◽  
2018 ◽  
Vol 24 (02) ◽  
pp. 811-833 ◽  
Author(s):  
Bailu Teng ◽  
Huazhou Andy Li
Keyword(s):  
Fluid Flow ◽  
Transient Flow ◽  
Flow Behavior ◽  
Transient Behavior ◽  
Finite Conductivity ◽  
Linear Flow ◽  
Pressure Transient ◽  
Proposed Model ◽  
Elliptical Flow ◽  
The Matrix

Summary Field studies have shown that, if an inclined fracture has a significant inclination angle from the vertical direction or the fracture has a poor growth along the inclined direction, this fracture probably cannot fully penetrate the formation, resulting in a partially penetrating inclined fracture (PPIF) in these formations. It is necessary for the petroleum industry to conduct a pressure-transient analysis on such fractures to properly understand the major mechanisms governing the oil production from them. In this work, we develop a semianalytical model to characterize the pressure-transient behavior of a finite-conductivity PPIF. We discretize the fracture into small panels, and each of these panels is treated as a plane source. The fluid flow in the fracture system is numerically characterized with a finite-difference method, whereas the fluid flow in the matrix system is analytically characterized on the basis of the Green's-function method. As such, a semianalytical model for characterizing the transient-flow behavior of a PPIF can be readily constructed by coupling the transient flow in the fracture and that in the matrix. With the aid of the proposed model, we conduct a detailed study on the transient-flow behavior of the PPIFs. Our calculation results show that a PPIF with a finite conductivity in a bounded reservoir can exhibit the following flow regimes: wellbore afterflow, fracture radial flow, bilinear flow, inclined-formation linear flow, vertical elliptical flow, vertical pseudoradial flow, inclined pseudoradial flow, horizontal-formation linear flow, horizontal elliptical flow, horizontal pseudoradial flow, and boundary-dominated flow. A negative-slope period can appear on the pressure-derivative curve, which is attributed to a converging flow near the wellbore. Even with a small dimensionless fracture conductivity, a PPIF can exhibit a horizontal-formation linear flow. In addition to PPIFs, the proposed model also can be used to simulate the pressure-transient behavior of fully penetrating vertical fractures (FPVFs), partially penetrating vertical fractures (PPVFs), fully penetrating inclined fractures (FPIFs), and horizontal fractures (HFs).

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