A Novel Method for Performance Analysis of Compartmentalized Reservoirs

Abstract

-This paper presents a simple analytical model for performance analysis of compartmentalized reservoirs producing under Constant Terminal Rate (CTR) and Constant Terminal Pressure (CTP). The model is based on the well-known material balance and boundary dominated flow equations and is written in terms of capacitance and resistance of a production and a support compartment. These capacitance and resistance terms account for a combination of reservoir parameters which enable the developed model to be used for characterizing such systems. In addition to considering the properties contrast between the two reservoir compartments, the model takes into account existence of transmissibility barriers with the use of resistance terms.The model is used to analyze production performance of unconventional reservoirs, where the multistage fracturing of horizontal wells effectively creates a Stimulated Reservoir Volume (SRV) with an enhanced permeability surrounded by a non-stimulated region. It can also be used for analysis of compartmentalized conventional reservoirs. The analytical solutions provide type curves through which the controlling reservoirs parameters of a compartmentalized system can be estimated. The contribution of the supporting compartment is modeled based on a boundary dominated flow assumption. The transient behaviour of the support compartment is captured by application of "distance of investigation" concept. The model shows that depletion of the production and support compartments exhibit two unit slopes on a log-log plot of pressure versus time for CTR. For CTP, however, the depletions display two exponential declines. The depletion signatures are separated by transition periods, which depend on the contribution of the support compartment ( i.e. transient or boundary dominated flow).The developed equations can be implemented easily in a spreadsheet application, and are corroborated with the use of a numerical simulation. The study provides a new and nonconventional insight into the use of production data as an aid in the understanding of hydraulically fractured tight formations and compartmentalized conventional reservoirs.

Thermal Behavior Analysis of Geothermal Systems under the Influence of Rock-Formation Structures

“…The essence, of heterogeneity study is focused to identify the features that impact the system performance. The existence of faults and throws mark the difference between sealing and leaking each layer differently [16]. Heterogeneity of geothermal reservoirs is mainly due to its volcanic origin which is the cause of great variations both in physical and thermodynamic properties of the rock system [5].…”

“…To achieve this goal, it is necessary to determine the heat source, the petrophysical rock properties, and the hydrologic feed source with accuracy. The integrated characterization plays an important role for establishing the exploitation management programs as well as the feasible and sustainable growth of a geothermal field [12][13][14][15][16][17][18][19][20].…”

A Genetic Algorithm Integrated with Monte Carlo Simulation for the Field Layout Design Problem

“…That is, we chose a simpler PI model because it represents the reality in a sufficient level of detail for the objectives of this paper. Therefore, PI models that consider prior geological knowledge such as compartmentalized and unconventional reservoirs, as presented in Shahamat et al (2016), or PI models that analyze interwell connectivities by assessing the coupling of wells between themselves and the geological formation, as presented by Noetinger (2016), are recommended for a more detailed analysis.…”

Ensemble-based method with combined fractional flow model for waterflooding optimization

“…Theorical arguments about the physical meanings and the strategies to obtain CRM parameters can be found in (Gentil, 2005;Noetinger, 2016). For example, Shahamat et al (2016) used the capacitance and resistance concept and developed a mathematical model for compartmentalized reservoirs and detailed analytic solutions.…”