The operator has been very active drilling in the Williston Basin including the Bakken for several years now. As development progresses, lateral sections were steadily increased and are now in the 10,000ft range and with this, the average days in completing the section has also increased to 14 days. These wells have been drilled conventionally since the beginning of the campaign and have been plagued with problems such as stuck pipe, mud loses, pressure issues to cite some examples.
A test well was agreed for Managed Pressure Drilling (MPD) to see if this can solve the issues observed. MPD design for an optimized mud weight and surface backpressure schedule were utilized in the whole production section including for tripping and liner run operations. For the test well, a total of 9622ft of lateral was drilled for 7 days including casing run and cementing. Performance-driven application of MPD effectively reduced in half the operating days.
With the successful application of MPD, it has managed to achieve the main objective which is to reduce the operating days for drilling the production section. This was achieved through the ROP improvements due to a lower mud weight and application of back pressure to minimize surface gas and having the MPD package to handle the gas at the surface while drilling.
In the span of three months starting from that first test well for MPD, the campaign continued with using the technology and one more rig was added. So far 5 wells have been completed with improvements from MPD with reduced operating time. Lessons learned and continuous training of the field operating team have enabled for the drilling campaign to utilize this technique further in synergy with the other field service groups.
For this paper, the specific MPD operations will be described including the liner run procedures for the wells drilled so far and the key lessons for the continuous application of MPD to the Bakken drilling campaign in the Williston Basin.