M-I SWACO announced the release of the LOW PRESSURE AUTOCHOKE CONSOLE* (LPAC*) unit, a precision-built choke console that provides accurate and economical control of the AUTOCHOKE* unit during managed pressure drilling (MPD), underbalanced drilling (UBD) and other low surface pressure operations.
The LPAC unit allows the operator to directly set and maintain the desired back-pressure on the well using either the Local Hydraulic Power Unit (HPU) Console or the Remote Human Machine Interface (HMI) Panel near the driller. The LPAC unit enables seamless transition between AUTOCHOKE units, while simultaneously controlling two units. The unit can maintain pressure for more than two hours after loss of rig air and up to one hour after loss of rig power thanks to the hydraulic accumulator, air storage tank and uninterruptible power supply.
The LPAC unit was recommended when an operator in Texas planned on drilling a series of laterals underbalanced, while holding near-constant bottomhole pressure during connections. During the drilling phase, the LPAC unit held 350 psi back-pressure on the casing, allowing the operator to strip to the bottom under pressure. With the LPAC unit dialed in on the correct casing pressure, the rate of penetration increased by 15 – 30 ft/hr (5 – 9 m/hr), reducing the drill time by 10 days and saving an estimated $1 million.
The unit’s sunlight-readable touch screen panels ensure accurate readings in any weather condition and allow for precise pressure inputs to the AUTOCHOKE units. Screens display additional operating parameters including casing and drill pipe pressures, pump rates, strokes and diagnostics.
The Remote Human Machine Interface can be placed anywhere, allowing the choke operator to work in close proximity to the driller throughout the MPD or UBD section of the well. The Remote HMI comes standard with the LPAC unit. A built-in arbitration scheme allows the logical transfer of control between the remote HMI and the Local HPU. The LPAC unit is also equipped to be controlled by third party software.