Pressure pulse fracturing bypasses near-wellbore damage
Increased production in high water-cut field a challenge
An operator in southeast Asia wanted to reverse declining production
from an old field where production is currently driven by waterfloods and most
of the wells have ESPs.
Water cut in the field is in the range of 85%99%, and wells are
constantly being worked over. Zones with high water cut are squeezed off while
other zones are reperforated. Further, many of the thinly laminated sand layers
have proved difficult to produce because of nearwellbore damage.
The operator invited Schlumberger to initiate a project to determine the
best solution for increasing production.
Postperforating propellant pulse selected to fracture the near-wellbore
The first step in the field trials was reperforating two wells with
PowerJet Omega deep penetrating charges, resulting in productivity increases of
200% and 325%from 150 bbl/d to 450 bbl/d in the first well and from 150
bbl/d to 640 bbl/d in the second well. Flow rates were stable throughout the
first 30 days of production.
To further improve productivity, the operator decided to fracture the
near-wellbore area with a postperforation propellent pulse. The propellent
pulse system effectively treats intervals by combining a solid propellant with
an ignition device that controls the burn radially inward.
Because the propellant burns very rapidly instead of detonating like an
explosive, the generated pressure pulse is powerful enough to fracture the
formation without damaging the casing or adjacent plugs or packers. This
feature enables precise treatment of intervals that would not be reached by a
standard hydraulic fracturing job, warranting consideration of the propellent
pulse system for the desired near-wellbore treatments.
Based on well and formation parameters and the design of the propellent
pulse toolstring, propellent pulse planner software was used to design a job
that would produce a 2,500-psi pressure pulse to create near-wellbore