Henry Lopez, Doug Walser, Mark Malone, & George Woo, BJ Services Co.
A novel process has been developed to reduce the polymer damage associated with aqueous fracture treatments inclusive
of the filter cake and polymer residue and their detrimental effects to fracture conductivity, formation permeability,
and the resultant oil and gas production. This novel approach differs from conventional breaker applications in that the
formation is first treated with breakers and then the fracture treatment is performed. The process advances that a
"Fracture Pre-Treatment" fluid enriched with breakers is pumped ahead of the primary fracture treatment and proppant.
The process also advances that the breakers coat the formation matrix to include the formation surfaces, pore throats,
and permeable network through natural leak-off prior to the dynamic deposition of the filter cake during the fracture
treatment.
Since the breaker enriched Fracture Pre-Treatment fluid is pumped prior to the main body of the fracture treatment
(and proppant), the dynamic pressure differential between the fracture and the formation contains the Fracture Pre-
Treatment fluid behind or in the formation during the fracture treatment. Thus the main body of the fracture treatment
is unaffected by the Fracture Pre-Treatment fluid. The fracture treatment is completed in the conventional manner with
standard breaker concentrations, the well is shut in to allow the fluid to break, and the flow-back process is then
initiated. During the flow-back of the treatments the pressure dynamics are reversed releasing the fracture treatment
and Fracture Pre-Treatment fluids. The breaker enriched Fracture Pre-Treatment fluid flows from the formation matrix
into the fracture sweeping it with a concentrated breaker solution.
This unique process concentrates the breakers on the formation side of the filter cake, increases the total mass of the
breakers that can be applied and further exposes the filter cake and polymer residue to the breakers upon flowback of
the fracture treatment and Fracture Pre-Treatment fluid. These combined factors enhance the degradation of the filter
cake and polymer residue, thereby promoting increased regained fracture conductivity, formation permeability, and
further enhancing oil and gas production.