Expanding the Hydraulic Fracturing Options on Reservoirs with Water Zones in Western Siberia

摘要

Hydraulic Fracturing in Western Siberia, Russia is a common practice that the need of stimulating wells in mature oil fields cannot be limited to non-complicated reservoirs. Wells requiring hydraulic fracturing with water zones either above or below is what we mean as reservoirs that require techniques that are out of the ordinary and day to day operations. A technique using dry solid material to contain the hydraulic fracture job within the zone of interest has been used in several wells and will be presented in this paper. The oil field Nivagalskoe which is located in Nizhnevartovsk area, Western Siberia, Russia is considered a mature oil field where due to the low value of the reservoir permeability, hydraulic fracturing these reservoirs require more than a skin bypass frac. Achieving a lengthier propped frac and descent net pressure increase is always a challenge on any hydraulic fracturing job execution but is always a must for the oil fields in the Nizhnevartovsk area. The challenge becomes when there are water zones close to the zone of interest to be stimulated via hydraulic fracturing. The objective is only not to design a job that will be limited in height by optimizing parameters commonly used in limiting frac geometry but to guarantee at best that the frac will not grow into the water zone. Several case histories will be presented where all cases the water cut was measured before and after the hydraulic fracturing job. The technique used and recommendations will be presented to optimize future jobs. All other options to limit frac geometry considered will also be presented.