| Title | LESSONS LEARNT IN USAGE OF PRESSURE WHILE DRILLING (PWD) TO JUSTIFY DRILLING DECISIONS |
|---|---|
| Authors | O. Goh, G. Allan, and B. Carson |
| Year | 2021 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Pressure While Drilling, Well Capacity, Injectivity Index |
| Abstract | Pressure-While-Drilling (PWD) is a pressure sensor installed as part of the bore hole assembly (BHA) on the drill string. The PWD tool provides real time measurement of the pressure in the annulus at depth and can be used to monitor hole conditions such as the clearing of cuttings or used in early detection of well control issues. During Mercury’s previous drilling campaign in 2016-2017, a methodology was developed by the reservoir engineering team to use the data obtained from PWD to quantitatively determine well capacity in real time. This information can then be used in lieu of the traditional stage test (which can induce additional cost for rig time) to drive drilling decisions such as side-tracking, deepening or early completion of the well. The PWD methodology yielded useful results during the 2016-2017 drilling campaign and therefore, the similar methodology was applied in the 2019-2020 campaign on two production wells and one injection well drilled. This paper presents the lessons learnt from the usage of PWD in Mercury’s 2019-2020 drilling campaign and provides specific examples of the drilling decisions that were made based on the PWD methodology. This paper also highlights the limitations of the PWD methodology and covers recommendations to improve the speed and accuracy to translate the PWD results into well capacity during a drilling campaign. |