The Impact of Pertinent Parameters on the Design of Hydraulic Fracturing in Gas Condensate Reservoirs (2005)

The impact of pertinent parameters on the design of hydraulic fracturing in gas condensate reservoirs Gustavo Adolfo Carvajal; Gustavo Adolfo Carvajal Search for other works by this author on: This Site Google Scholar Ali Danesh; Ali Danesh Heriot Watt University Search for other works by this author on: This Site Google Scholar Mahmoud Jamiolahmady; Mahmoud Jamiolahmady Search for other works by this author on: This Site Google Scholar Mehran Sohrabi Mehran Sohrabi Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Europec/EAGE Annual Conference, Madrid, Spain, June 2005. Paper Number: SPE-94074-MS https://doi.org/10.2118/94074-MS Published: June 13 2005 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Carvajal, Gustavo Adolfo, Danesh, Ali, Jamiolahmady, Mahmoud, and Mehran Sohrabi. "The impact of pertinent parameters on the design of hydraulic fracturing in gas condensate reservoirs." Paper presented at the SPE Europec/EAGE Annual Conference, Madrid, Spain, June 2005. doi: https://doi.org/10.2118/94074-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Europec featured at EAGE Conference and Exhibition Search Advanced Search AbstractFracturing is the most common well stimulation technique in gas condensate reservoirs.Flow of black oil and dry gas in induced fracture systems has been widely studied by numerical simulation, core-flood and well tests.However, the flow behavior in fractures surrounding a gas condensate well, which could be significantly different to that of conventional systems, has not been fully understood.Most of the available literature has quantified the negative effect of condensate banking and inertial (non-Darcy) flow on well productivity, giving a pessimistic view of the gas rate in these systems. The above studies have neglected improvement in the gas and condensate relative permeability by increasing rate due to positive coupling of the two phases.In this work, measured values of permeability, single-phase inertial factor and relative permeability of a propped fracture were used to evaluate the effect of pertinent parameters on fracture performance more realistically.A reservoir simulator was used to develop realistic models of flow in fractured systems. A comprehensive sensitivity analysis on the impact of fracture characteristics on well productivity for different fluids and rock properties was conducted. The results demonstrated that not only inertia was important but also positive coupling strongly affected the flow performance.In particular for a tight formation, whereby fracturing is most effective, positive coupling in the matrix can overcome negative inertia in the fracture region.The results also reveal the important contribution of the fracture width, as wide fractures reduce the inertial effect significantly.Furthermore, we will show that increasing the fracture length does not necessarily lead to higher gas well productivity as there are optimum values for any given set of parameters.IntroductionThe mechanisms that affect fracture performance in gas condensate systems such as condensate banking and inertial flow have been widely studied [1–3]. However, the positive coupling effect, that is, improvement of gas and condensate relative permeability by increasing velocity, in fractured wells has not been yet fully analyzed. The positive coupling, as a flow mechanism, is certainly known in flow around un-fractured wells [4–7].But the new concepts related to the flow rate and capillary number have not yet been incorporated into gas condensate deliverability models for fractured wells.Reports by Wang et al. [8] and Indriatti et al. [9] are the only available literatures that explore the effect of capillary number in their study. They adjusted the relative permeabilities with the capillary number for the effect of interfacial tension.The main objective of this study is to evaluate the impact of positive coupling and inertial effects on design of fracturing and prediction of fractured well performance.We shall analyze the significance and impact of several parameters, describing rock, fracture and fluid properties that can influence the process. The ECLIPSE [10] reservoir simulator was used to develop realistic models of flow in fractured systems and to evaluate the effect of pertinent parameters on fracture performance.Fractured Well ModelingGenerally, vertical fractures are simulated using Cartesian models rather than radial ones.It is basically due to its flow regime, which is considered to be mainly linear from the reservoir into the fracture face, and through the fracture towards the wellbore. However flow can be considered pseudo-radial far way from the fracture.The significance of the latter flow regime depends upon how much the fracture improves the productivity index compared to an un-fractured case.Furthermore, geometry representation of radial model of a fracture in the simulator is unrealistic.That is, it exhibits an increase in thefracture width, away from the well.The width has a strong effect on velocity as it is linked directly to the flow cross sectional area. This was confirmed in a sensitivity study whereby the effect of inertia was found to be unrealistically minimal for a fractured well model in radial system due to inaccurated calculations of velocity.Although shape factors were developed and included in simulation to alleviate the above problem, it was concluded that a Cartesian coordinate system could capture flow in a fractured well model more realistically. Keywords: gas condensate reservoir, upstream oil & gas, fracture length 150, condensate reservoir, coupling, positive coupling, gas production rate, inertia, fracture length, different fracture length Subjects: Hydraulic Fracturing, Unconventional and Complex Reservoirs, Gas-condensate reservoirs This content is only available via PDF. 2005. Society of Petroleum Engineers You can access this article if you purchase or spend a download.