At Balance TE MPD Closed Circ

Value proposition - quantify the value that MPD will deliver relative to strong economic drivers

Drill time and/or cost savings
Increased access to reserves in depleted reservoirs or smaller reservoirs that may be uneconomic for conventional drilling
The number of wells that cannot be drilled conventionally but can be with MPD
Improved safety

MPD equipment and rig compatibility

Identify the optimum location on the rig for the MPD equipment keeping in mind its safety specifications and deck load ratings of offshore rigs
Quantify the amount and size of the piping that will be needed to interconnect the MPD and rig equipment, the pressure drop in the piping, the number of “elbow” connections, and its pressure rating
Identify the modifications that will have to be made to the rig equipment to connect the MPD
Ensure sufficient space is available between the top of the BOP stack and the rig floor for installation of the RCD

Drilling hydraulics - an essential part of drilling and well design but critical for MPD applications

Drilling pressure window must be defined based on the pore pressure / fracture gradient (PP/FG) plot
Establish the minimum BHPs for well control and borehole stability and the maximum BHP for lost circulation
Model the casing and drill pipe geometries with the planned mud properties at optimum drilling parameters
Define the EMW of the AFP while circulating at planned drilling rates
Evaluate alternate mud weight scenarios with MPD to reduce static mud weight and ECD at the modeled flow rates, rotary speed and penetration rate
Define the pressure reference or set point to be held while drilling and during connections
Define the tolerance window around the setpoint pressure that establishes the minimum and maximum allowable fluctuations

Personnel Training

Plan and conduct Hazard Identification (HAZID) and Hazard Operability (HAZOP) workshops to review the MPD system and define the potential risks

Identify the corresponding mitigation or response actions for each risk element

Categorize the HAZID results into drilling, connection, and tripping events and their relative risk (e.g., under-pressure or over-pressure)

Conduct training in at least two stages - classroom and on-site - to prepare the rig and service crews

In the classroom introduce MPD concepts, define the value and case for action, provide details of the MPD system components, and review the contingency plans defined in the HAZOP workshops

At the well site provide pre-tour presentations and walk through equipment installation and operation

It is highly recommended to test the MPD system functionality and practice contingency plan actions during the trip prior to drilling the shoe

Procedures - develop procedures for every major phase of the particular MPD operations which should include the following:

Testing and commissioning of the primary pressure control system after arrival at the point of embarkation and prior to shipment to the well

Placement, rig up, piping layout and connection, and power connection,

Formal wellsite testing and commissioning involving specific operating scenarios and contingencies

Making the transition from pumps-on while drilling to pumps-off to make a connection and back

Describe the method for tripping out of the well before reaching TD

Any task that will affect the pressure regime of the well such as:

Picking up off bottom

Reducing the pump stroke rate

Stopping the mud pumps suddenly

Trips in and out of the hole

Plugged drill string or nozzles

Mud pump washout

Change in mud properties

Increasing ROP (induces more cuttings in the annulus)