The OrganoSEAL gel entered the near-wellbore area through the screens,
plugging the water in the formation matrix.
The main challenge was ensuring that the packers were placed at the
right depth. When water shutoff treatment is pumped inside a reservoir, it
plugs the formation matrix in that zone, preventing further fluid breakthrough.
The CoilFLATE packers needed to be placed above and below the 43-m [141-ft]
water-producing section and the chemical barriers pumped into the center of
this section to isolate it without shutting off oil production from the
surrounding areas. The slotted liners added an extra layer of complexity
because if the treatment spreads beyond the water zone, it could get into slots
of the liners and potentially damage parts of the reservoir.
Reduced water cut in both wells
A detailed assessment with logging data was made of well B, and it was
determined that the bottom zone of the well was producing water. It was
suspected that there was a leak in one of the swell packers that had been
previously placed by the operator. The decision was made to deploy a CoilFLATE
packer above the screens at the top of a blank section at 1,775 m [5,823 ft] to
isolate the bottom section of the well. The packer was set and the wellbore was
cleaned in preparation to be filled with SqueezeCRETE solution. The cleaning
prevented the cement from sticking to the inside of the completion and the
surrounding formation matrix. The SqueezeCRETE solution was pumped through the
coiled tubing below the CoilFLATE packer, filling the completion and annulus
between the formation matrix and the completion. The precise placement of the
CoilFLATE packer prevented the chemical barrier from seeping above the packer
and into the producing zone of the annulus.
Prior to treatment, both wells had a water cut level of above 90%. Four
months after the treatment, the water cut for well A had decreased to 70% and
well B had a water cut of 80%, leading the operator to evaluate the potential
of similar treatments for other wells shut in prematurely because of excessive
water cut.