Packer Performs Successfully in Single Trip, Saving Operator Millions of Dollars in Blowout Avoidance
Challenge – This was the longest well that the operator had drilled in the region and the most complex in terms of architecture. The well construction consisted of 12,831 feet (3,911 meters) of mixed 13 5/8-in. and 13 3/8-in. casing, as well as 13,330 feet (4,063 meters) of 9 5/8-in. liner. The ERD lateral kicked off at 5,643 feet (1,720 meters) and continued all the way to 24,508 feet (7470 meters), at an inclination up to 84–87° all through the lateral.
The big-bore architecture of the well, along with its steep trajectory and depth, made it very challenging to run the packer to depth and to set it successfully. By design, this packer is activated and set by applying compression to shear a shear ring installed in the packer. However, in this case, due to the high amount of drag expected during the run in hole, there was a risk that excessive compression might accidentally shear the shear ring prematurely. Furthermore, the client’s drilling mud was new for the region, so historic information on previous friction factors was not available. This made it necessary to estimate various friction factor scenarios in the torque and drag (T&D) modeling. There was a risk that, if the friction factor was higher than expected, the work string would lose all its weight before reaching target depth, thus exceeding the shear ring rating installed in the packer and setting it too high, or simply not having enough weight available to get the string to the desired depth and to carry out the operation in a single trip.
Solution – For this complex task, Halliburton recommended its CleanWell® Inflow Tech® packer – a compression-set, retrievable, negative-test packer, activated by shearing a predeterminedvalue shear ring. This packer has a simple design and can be rotated in the hole with up to 80 rpm in tension.
Extensive T&D simulations were performed by Halliburton engineers to validate the run and determine if it would be achievable. To counteract the expected excessive compression at the packer due to high drag, a shear ring with the highest rating (65 kips) was selected. It was also recommended that the operator closely monitor the hook load while running in hole to determine the drag friction factor for T&D model calibration in order to avoid shearing the shear ring prematurely. Primary and backup packers were prepared in a Halliburton shop in Sakhalin, Russia, and then sent to this offshore location.
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