RUNNING THE BOP AND RISER SYSTEM 1. BOP Stack And Riser Preparation

After 20" casing has been run and cemented, the BOP stack and the riser will be run and latched.

The BOP stack must be checked and tested and the riser elements inspected in order to have the equipment ready to run as soon as possible after cementing the 20" casing.

The following is a list of suggested inspections and tests.

1) Open all rams.

2) Check the sealing elements for wear or damage.

3) Clean the bore and the ram cavities with a high pressure stream of water in order to be able to detect the presence of dents.

4) Replace the bonnet seals.

5) Visually inspect the annulars sealing elements.

6) Check for trash behind the rubber element of the spherical by measuring the ID of the element.

7) Pressure test the stack on the test stump to its rated working pressure (or to the working pressure of the wellhead connector if this is less than that of the BOP).

8) Function test the BOP through both pods. Each time a function is operated note the volume of the fluid used for the functioning and closing times. These figures are essential to determine whether or not the BOP and its control system are working correctly.

9) Pressure test the choke manifold.

10) Clean and inspect all connectors on the riser sections and pup joints to be used.

5.4.2. Running The Bop And Riser

Before running the BOP stack check the weather forecast and refer to the ‘Rig Operations’

manual for the maximum vessel motion (heave, roll and pitch) for running BOP.

Running procedures vary from rig to rig due to the specific design of the stack and to the handling system (gantry cranes, fork lifts, trolleys, etc.) used for moving the BOP in and out of the moonpool area. There are also a variety of ways to land the BOP stack. For this reason provision of detailed procedures is not possible therefore the following steps are only generic.

1) Skid the BOP in the moonpool to a position directly under rotary table.

2) Insert the guide lines into the posts of the stack.

3) Place the marine riser handling spider on the rotary table.

4) Pick up a joint of marine riser using the marine riser handling sub.

5) Lower the marine riser joint through the handling spider and make up to the top of the ball/flex joint.

6) Lift the BOP stack and install a new ring gasket on bottom the of wellhead connector.

7) Make sure the bulls-eye angle indicators are installed above and below the ball/flex joint. Ensure they are visible to the subsea TV system.

8) Lower the BOP stack through the splash zone and land the riser on the handling spider. The first riser joint above the BOP should be long enough to allow the stack to be run into the water to dampen its motions.

9) Continue to run the marine riser on riser joints. The riser couplings should be made up in accordance with the particular manufacturer's recommended procedures. The correct make up and preload of each coupling should be verified prior to its use as a tensile member.

10) Test the choke and kill lines every third joint.

11) Install the required riser pup joints to obtain the correct space out, such that the telescopic joint will be at mid stroke.

12) Pick up the telescopic joint (also called slip joint), locked in the closed position, and install onto the riser assembly. Lower the riser assembly until the outer barrel is at the spider. Land the outer barrel on the spider level.

13) Stroke out the slip joint inner barrel. Remove the handling spider and lower the telescopic joint through the rotary table until the riser tensioning cables can be installed on the riser tensioning ring.

On some rigs the slip joint is run in the collapsed position by using an extra joint of riser temporarily installed above the telescopic joint.

Either the shoe on the inner barrel and/or the pins that lock the slip joint in closed position, should be designed to support the combined submerged weight of the stack and riser as well as dynamic loads.

5.4.3. Landing The BOP Stack

1) Tension the guide lines for landing the BOP stack.

2) Run the TV camera or ROV. Focus on the lower extremities of the BOP stack.

3) Open the motion compensator.

4) Lower the BOP stack until the connector lands on the wellhead housing. Observe the landing with the TV.

5) Latch the connector. With the Motion Compensator make a pick up test of 50,000lbs (15t) above the stack weight to verify the connector is correctly locked down.

6) Adjust the riser tensioners to full working tension as per the rig operating manual and/or riser analysis programme. During the life of the well, it may be necessary to vary the riser tension due to an increase in mud weight or weather conditions.

7) Reduce the tension in the guide wires.

8) Install the choke and kill hoses to the terminal fittings on the slip joint.

9) Install the slip joint packing control lines.

10) By pumping down choke or kill line, test the wellhead connector and the casing against the blind/shear rams to the pressure indicated in the drilling programme.

11) Install the diverter package and rotary table.

5.4.4. Testing The BOP Stack

1) Retrieve the 18³/4” nominal seat protector. Do not land the test plug on the seat protector since test pressure will force the protector down, swedging it into the housing.

2) Run the BOP test plug.

3) Fill the running string to the top with water. The string must remain open to atmosphere during the entire test.

4) Pressure test the BOP stack as per Eni-Agip Division and Affiliates Well Control Policy using either one of the two pods. A BOP function test must then be performed on the other pod.

5) Recover the BOP test plug.