Performance Report: FORM-A-SQUEEZE LC Plug Reduces Losses in the U.S. Gulf of Mexico

Western Gulf of Mexico

Challenge: A major international operator working in the U.S. Gulf of Mexico observed a close tolerance between the mud weight and fracture gradient when drilling below a 7⅝-in. expandable liner. Seepage losses at rates of 1-3 bbl/hr were observed while drilling sand sections.

Regular additions and high concentration sweeps maintained background LCM of calcium carbonate M, C and XC as well as G-SEAL additive in the Rheliant synthetic-base mud at 15-20 lb/bbl. The drilling team closely monitored ECD using an APWD tool. Increases in ECD were reduced by lowering ROP and controlling the flow rate. Drilling stopped so the well could be circulated when the ECD increased near an established threshold that was 0.5 lb/gal above the mud weight.

As drilling continued, however, complete returns were lost while reaming back to bottom to make a connection. Circulation was attempted at a reduced rate with minimal returns. The hole had minimal mud losses when static. Based on the drilling conditions, the losses appeared to be on bottom.

Solution: The drilling team selected the FORM-A-SQUEEZE lost circulation plug as the circulation-loss solution because of its successful application while drilling the previous interval. Factors in selecting the FORM-A-SQUEEZE product were:

1. The speed with which the material could be mixed
2. Simplicity in spotting the pill (no spacers or surfactant/solvent pills required)
3. No restrictions on pumping time to put the pill in place. Low flow rates could be used to minimize losses to the formation that could cause ballooning issues on future connections and trips.

The team developed a procedure for pumping the pill to the bit along with 15 bbl into the annulus. The remaining pill was pumped out of the drill string while pulling the bit inside the liner. This minimized the contamination of the pill and placed the bit one stand above the slurry before the squeeze operation was initiated. The entire open-hole section was filled with the FORM-A-SQUEEZE pill to cover potential loss zones.

Result: The drilling team built 110 bbl of slurry using 200 sacks of FORM-A-SQUEEZE product (80 lb/bbl) combined with 80 bbl of synthetic-base fluid, and 400 sacks of barite. After the slurry was built, it was pumped down the drill pipe, and 15 bbl was pumped into the annulus prior to pumping and pulling the pipe to get the bit above the slurry.

Once the bit was above the slurry, the annular preventer was closed, and squeeze pressure was applied using the cementing unit at a pump rate of 0.5 bbl/min. After 4.5 bbl was pumped, the squeeze pressure built up to 284 psi. Pumping was stopped for three minutes, which allowed the pressure to drop to 160 psi. One additional barrel of mud was squeezed, and the pressure built back to 284 psi. The pumps were stopped for three additional minutes, and the pressure dropped down to 165 psi. The pumps were started again at 0.5 bbl/min.

An additional 45 bbl of fluid was squeezed into the formation, and the pressure built up to 325 psi. The pumps were stopped for six minutes, and the pressure dropped to 197 psi. The team then squeezed 1.5 bbl of mud into the well, which caused the pressure to build up to 339 psi. At this point, the pumps were shut down for another six minutes, which allowed the pressure to drop to 192 psi.

Another 0.5 bbl of mud was squeezed into the formation, which pushed the pressure back up to 330 psi. At this stage, the well was shut in for 30 minutes, which allowed the pressure to drop to 142 psi. A total of 53.5 bbl of slurry was squeezed into the well in the course of this project. When the slurry was completely circulated, the pipe was washed and reamed to bottom. Using the FORM-A-SQUEEZE lost circulation plug reduced mud losses from total loss to a loss of 2-3 bbl/hour as drilling continued.

Download: FORM-A-SQUEEZE LC Plug Reduces Losses (0.61 MB PDF)

Related services and products