Field Results: Effect of Proppant Strength and Sieve Distribution UponWell Productivity

摘要

Development of the Pinedale Anticline (PDA) of westernrnWyoming is proceeding at a rapid pace. During the past fivernyears, approximately 500 million pounds of proppant havernbeen placed into nearly 200 new wells. Despite this highrnactivity level, no clear consensus has emerged from thernvarious operators as to the optimal stimulation design.rnProppant costs range from less than 20% to greater than 65%rnof the stimulation service company ticket dependent onrnproppant type selected. For one operator, proppant costsrnrepresent approximately 30% of the total completion cost andrnare a target for cost reduction efforts. These cost reductionrnefforts must be balanced with the economic value of proppantrnconductivity and its relationship with effective fracture half-length.rnThis paper summarizes results from a field trial that wasrnimplemented to investigate the effect of proppant selectionrnupon productivity from low-permeability (0.0006 – 0.015 md)rnformations of the Pinedale Anticline. This study compares thernproduction from 452 fracture treatments in 30 new wellsrncompleted by Shell Rocky Mountain Production during thernpast three years. Production logs are used to compare thernproductivity of fractures propped with 20/40 sand, 20/40 resin-coatedrnsand, 20/40 economy light-weight ceramic, broad-rnsieved intermediate strength, and 20/40 intermediate strengthrnproppants. The results from this study are believed to be thernfirst published field comparison of broadly-sieved and tightly-sievedrnceramics.rnThis trial predominantly maintained a consistentrnstimulation strategy to reduce complexity and uncertainty inrnthe analysis of the proppant selection evaluation. Proppantrnselection was varied by stage dependent on depth and geologicrnintervals to provide reliable offset comparisons. Results arerncategorized by geologic interval to reduce uncertainties from variations in reservoir quality and pressure differentials tornmore accurately assess the impact of altering proppant type.rnEconomic analyses are presented to illustrate the most costrneffective products to incorporate into each fracture treatment.rnActual field results are compared to model predictions andrnlaboratory results to determine whether proppant strength andrnsieve distribution affect production in a predictable manner.