PROP TRANSPORT IN A LARGE VERTICAL MODEL

Abstract

Prop Transport In A Large Vertical Model John A. Sievert; John A. Sievert Conoco Inc. Search for other works by this author on: This Site Google Scholar Harry A. Wahl; Harry A. Wahl Conoco Inc. Search for other works by this author on: This Site Google Scholar Peter E. Clark; Peter E. Clark University of Tulsa Search for other works by this author on: This Site Google Scholar Michael W. Harkin Michael W. Harkin Dowell Search for other works by this author on: This Site Google Scholar Paper presented at the SPE/DOE Low Permeability Gas Reservoirs Symposium, Denver, Colorado, May 1981. Paper Number: SPE-9865-MS https://doi.org/10.2118/9865-MS Published: May 27 1981 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Sievert, John A., Wahl, Harry A., Clark, Peter E., and Michael W. Harkin. "Prop Transport In A Large Vertical Model." Paper presented at the SPE/DOE Low Permeability Gas Reservoirs Symposium, Denver, Colorado, May 1981. doi: https://doi.org/10.2118/9865-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 Rocky Mountain Petroleum Technology Conference / Low Permeability Reservoirs Symposium Search Advanced Search AbstractA large vertical-slot model without fluid loss was used to evaluate the roles of fluid type, fluid viscosity, prop concentration and flow rate on prop transport and pack growth. Individual particle trajectories as well as overall pack growth were measured.With non-Newtonian fluids, changes in either prop concentration or gel concentration (viscosity) prop concentration or gel concentration (viscosity) produced significant changes in pack growth. By produced significant changes in pack growth. By contrast, a 0.03-Pa s (30-cp) Newtonian fluid system allowed the prop to settle so rapidly that no influence due to the variables of interest could be detected. A 0.06-Pa s (60-cp) Newtonian system showed a flow rate effect when the prop concentration was held constant.Observations made during the experiments indicate that some forces present in the gelled system were absent from the Newtonian system. Measured pack growth rates do not agree with those calculated pack growth rates do not agree with those calculated by substituting measured particle fall rates into existing mathematical models. This is true for both Newtonian and non-Newtonian fluids. Much work remains to be don * e before prop transport and deposition in vertical slots is adequately understood.IntroductionWell stimulation has become an indispensable part of hydrocarbon production operations. The part of hydrocarbon production operations. The major portion of the stimulation treatments is carried out by transporting prop into hydraulically fractured hydrocarbon-bearing formations in order to provide a high-permeability channel to conduct provide a high-permeability channel to conduct fluids to the well bore. The success of such treatments depends on the location and condition of the prop at the end of the job. All the time and money spent developing and perfecting fracturing fluids, techniques, and equipment are peripheral to the central objective of placing prop in a slot or fracture so it will function as a highly conductive channel.In spite of the importance of prop placement, the literature contains relatively few papers which report results of studies devoted to slurry flow and prop deposition in vertical slots. One of the earlier studies of prop placement in a vertical slot was that of Kern et al. Babcock et al established the conditions for building an equilibrium pack in a vertical slot. Wahl described the transport of prop in a horizontal slot and developed empirical relationships to describe the prop placement. Others have presented results from prop placement. Others have presented results from transport studies in small vertical models and from mathematical models of the fracturing process. This paper presents qualitative results process. This paper presents qualitative results from a study in a large, vertical model.MODEL DESCRIPTIONThe physical model was described by the authors in an earlier paper. Modifications have been made to permit recycling the fluid back to the paddle mixers so that packs could be built in the paddle mixers so that packs could be built in the model without providing an excessive amount of storage for slurry. This change required continual monitoring of prop concentrations and fluid viscosity during the runs. The prop for all the tests was 20-40 mesh sand. A schematic diagram of the revised model is given in Figure 1.DATA COLLECTIONInitially data collection consisted of taking 16-mm movies of the slurry flowing past a grid of precisely known dimensions that was scribed into precisely known dimensions that was scribed into the transparent plastic sheet about 1.2 m (4 ft) from the juncture of the inlet header to the plastic model. This is about one-third of the way plastic model. This is about one-third of the way along the model. Concurrently, 35-mm pictures of the pack were taken to record settled pack height, elapsed time, etc. The movies were used to record particle trajectories as a function of the pack particle trajectories as a function of the pack height for the various sets of initial conditions. The variables were fluid type, fluid viscosity, prop concentrations, and flow rate. prop concentrations, and flow rate. P. 335 Keywords: mathematical model, plastic sheet, horizontal velocity, viscosity, prop concentration, pack growth rate, drilling fluids and materials, fracture, fall rate, particle Subjects: Drilling Fluids and Materials, Hydraulic Fracturing, Drilling fluid management & disposal This content is only available via PDF. 1981. Society of Petroleum Engineers You can access this article if you purchase or spend a download.