ABSTRACT
The successful hydraulic fracturing program at Prudhoe Bay would not have been possible in large part without an effective Coiled Tubing Unit (CTU) cement squeeze program. Many of these fracture stimulation candidates were wells which had been squeezed previously. Therefore, squeezed perforations were exposed to higher differential pressures during frac operations than were normally seen at Prudhoe. At the outset of the fracture stimulation program in 1990, squeeze perforations were failing when subjected to these extreme pressures.
It quickly became clear that more aggressive CTU squeeze techniques resulting in stronger squeezed perforations would be a necessity if the Prudhoe frac program was going to achieve its goals. A more aggressive CTU squeeze program was implemented in the Eastern Operating Area (EOA) by ARCO Alaska, Inc. in mid-1990. This paper documents the results of the new squeeze program which increased surface coiled tubing squeeze pressures from 1500 psi to 3500 psi for one hour. More resilient, acid resistant latex cement also became the standard in late 1990 for squeeze cementing. The implementation of this program has resulted in a squeeze success rate approaching 90%.
