A New Model for Matching Fracturing Fluid Flowback Composition (2007)

A New Model for Matching Fracturing Fluid Flowback Composition Rick David Gdanski; Rick David Gdanski Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Jim Dean Weaver; Jim Dean Weaver Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Billy F. Slabaugh Billy F. Slabaugh Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Hydraulic Fracturing Technology Conference, College Station, Texas, U.S.A., January 2007. Paper Number: SPE-106040-MS https://doi.org/10.2118/106040-MS Published: January 29 2007 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Gdanski, Rick David, Weaver, Jim Dean, and Billy F. Slabaugh. "A New Model for Matching Fracturing Fluid Flowback Composition." Paper presented at the SPE Hydraulic Fracturing Technology Conference, College Station, Texas, U.S.A., January 2007. doi: https://doi.org/10.2118/106040-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Hydraulic Fracturing Technology Conference and Exhibition Search Advanced Search AbstractRecovery of fracturing fluid is considered a critical aspect for achieving production performance that meets the expectations of fracture treatment designs. Fluid recovery is often described simply as a percentage of load recovery on a volume basis, without consideration of the composition of the recovered water. Some of this water may in fact be formation water and not original load water at all. Analysis of the ionic composition of the water can determine whether the recovered water is formation water or treatment water. This paper describes a new model that embodies the physics of flow during back-production of a fracturing treatment and incorporates a chemistry "layer" that allows for matching fracturing fluid flowback compositions. The model accommodates formation water having a separate composition from the fracturing fluid. The movements of sodium, potassium, chloride, sulfate, carbohydrate, boron, etc. are modeled during shut-in and production. The compositions of the produced water calculated by the simulator were compared to field production samples.The process of matching the produced water analyses after the fracturing treatment first required a good match of the produced water rates as a function of both time and the produced gas rates. Reservoir and fracture properties were optimized to match the water production. The ionic composition of the flowback water was then matched by adjusting various parameters that might affect how the water was recovered from the reservoir. The information obtained by adjusting these parameters includes relative permeability curves, capillary pressure curves, and some fracture structure details. Deviations of the model from the observed return profiles indicated areas where the understanding of fluid chemistry and physics of flow might be improved.IntroductionThe issue of propped fracture performance continues to be an important topic as our industry strives to recover ever more challenging reserves. The effective structure of a propped fracture is often much poorer than the engineering expectations of that fracture. A recent analysis has demonstrated that the evaluation and causes of inadequate production of fracturing treatments is quite complex.1 These complexities can result in different apparent answers when attempting to determine the effective fracture structure, such as the conductive fracture length and the conductivity of that conductive length. Determination of the resultant properties of the propped fracture is critical for understanding how to improve future treatments and for the development of new technologies to overcome the impediments to achieving the engineering expectations.Special fluid chemistry and chemical additives are often used to enhance the base physical properties of a propped fracture. However, the presence of those additives can create new impediments to cleanup. Fluid invasion into the matrix can severely reduce relative permeabilities and may cause clay damage if not properly designed. Special surfactants may be required if capillary pressure in the matrix is a dominant factor. Polymers used to enhance fracture structure can also create damage issues in the propped fracture. Well returns samples are occasionally collected and analyzed to give clues to the performance of those chemicals at downhole conditions.2,3The new method reported in this work brings together both the physics of fluid flow and the movement of chemicals in those fluids into a numerical simulator. Analysis of well returns and matching with a simulator can help provide new information regarding the performance of those chemicals, some reservoir properties of interest, and some fracture structure properties.Numerical ModelThe simulator for this project was written as a two-dimensional model and used a backward difference scheme using upstream transmissibilities and the simultaneous solution (SS) method4 to capture the physics of two-phase flow with capillary pressure. Gravity effects were ignored. The simulator takes advantage of symmetry to model ¼ of a square reservoir with a well at the center and a symmetrical fracture with two wings. The details of the physics of the fully implicit model have previously been reported.5 Keywords: fracturing materials, fracturing fluid, fracture length, flow in porous media, Upstream Oil & Gas, fracture property, hydraulic fracturing, Fluid Dynamics, concentration, proppant Subjects: Hydraulic Fracturing, Reservoir Fluid Dynamics, Fracturing materials (fluids, proppant), Flow in porous media This content is only available via PDF. 2007. Society of Petroleum Engineers You can access this article if you purchase or spend a download.