Demarchos examined 1000 hydraulic frac jobs from Western Siberia and noted that higher conductivity proppants and larger proppant volumes could significantly improve production. For a 3.8 md oil well in the Sugmutskoye field, doubling the amount of proppant and selecting a better proppant would result in a 50% increase in production, and payout the re-stimulation costs in one month.
Hydraulic fracturing has emerged as the compelling completion and stimulation procedure in Russian petroleum production credited to a large extent for the impressive production enhancement experienced in the last several years. We present in this paper approximately one thousand hydraulic fracturing jobs from Western Siberia and their performance is analyzed and compared with design and execution variables.
The well performance is measured through, among other things, the actual, field-derived, dimensionless productivity index (J[D]) and is compared against our concept of Unified Fracture Design (UFD) which has been used to physically optimize and maximize the productivity index from a hydraulic fracture treatment. We have demonstrated in the past that for a given mass of proppant there is a specific dimensionless fracture conductivity, which we called the optimum, at which the J[D] becomes maximum. The Proppant Number is a seminal quantity unifying the propped fracture and the drainage volumes and the two permeabilities, those of the proppant pack and the reservoir.
One of the important observations of our analysis is that the distributions of the achieved J[D] follow the theoretical curves, however there is a gap between the theoretically achievable and actually achieved J[D]. We evaluated the gap and identified measures to improve our fracture designs.
Conventional fracture designs can be extended considerably by injecting large proppant masses with far better proppantpack permeabilities within reasonable field and logistical constraints. It is against these two concepts, the desired optimum fracture conductivity for the injected fracture size, and the would-be "pushing the limits," design that we compare the already executed treatments. We provide critique and offer suggestions for design improvements.
Author(s): A.S. Demarchos, MJE Consultants; M.J. Economides, U. of Houston; I. Diyashev and V. A. Svaykin, Sibneft
Paper Number: SPE 94643