Extend setting depth by reducing casing weight and lowering drag force
Buoyancy-assisted casing equipment (BACE) allows operators to run casing to the bottom of highly deviated or horizontal wellbores. The “drag” between the casing and the formation in these wellbores often exceeds the hook weight of the casing, which can prevent tools from reaching the optimum setting depth. Shallow horizontal wells compound these challenges.
Minimizing these drag forces is the secret behind extending the reach of these wells. Halliburton's engineers have developed a technique that “floats” the casing into the wellbore by trapping air or lightweight fluid in the lower section of the casing string. The resulting buoyant chamber can extend to any length depending on the desired casing-weight reduction.
When used with Super Seal II® floating equipment, BACE traps lightweight fluids or air at the lower end of the casing string to reduce casing weight. The reduced casing weight results in lower drag force, which increases the possible running depth and minimizes the chances of the casing buckling or sticking.
Technical requirements of BACE include:
Float equipment (float shoe and collar) with a backpressure rating that exceeds the true hydrostatic pressure and temperature at total depth (TD).
Matching the BACE to the proper casing size, weight, grade, and thread type, and ensuring that the BACE assembly is properly rated to handle the applicable pressure and temperature.
When used with surface-release or subsea-release applications, a BACE releasing plug must be used.