BP repairs leak before injectivity test

Paula Dittrick
OGJ Senior Staff Writer

HOUSTON, Aug. 3 -- BP PLC repaired a small hydraulic leak in the capping stack hydraulic control system during its final preparations for the injectivity test, which was still expected to take place Aug. 3.

National Incident Commander and retired US Coast Guard Adm. Thad Allen told reporters the leak involved two valves on the kill side of the stack.

Allen expected the injectivity test to be completed on Aug. 3 followed by an evaluation of the information gained. During the injectivity test, crews will inject base oil into the choke line of the failed Deepwater Horizon blowout preventer to clear a flow path for heavy drilling fluid.

Transocean Ltd.’s Deepwater Horizon semisubmersible drilled the Macondo well in 5,000 ft of water on Mississippi Canyon Block 252. An Apr. 20 blowout resulted in an explosion and fire on the Deepwater Horizon, killing 11 people. BP operates the Macondo well.

The injectivity test also will help establish a pump rate for the drilling fluid, and will help crews understand the pressure associated with that pump rate, Allen said. If the test is successful, then crews will proceed with the static kill in which they will inject heavy drilling fluid into the top of the well.

In the static kill, crews will start by pumping 1 bbl/min of mud into the well, and that rate will be accelerated to 2-3 bbl/min depending upon the results of the injectivity test. It’s possible cement might be injected through the top of the well during the static kill.

Allen said at least the first of two relief wells will be completed even if the static kill is able to stop the flow of oil and gas in the Macondo well by pushing it back into the reservoir. The relief well will confirm that the flow of oil and gas has been stopped at the bottom of the well.

Contact Paula Dittrick at [email protected].