Historically, pressure measurements have been acquired with Wireline Formation Tester (WFT) tools. In highly deviated and/or lateral wells where tools are drill-pipe conveyed, this can be problematic and add significant expenses and operational risks. Formation Pressure While Drilling (FPWD) measurements minimize operational risks at reduced overall cost and increased operational efficiency. This is particularly relevant in high angle and/or lateral wellbores.
This paper discusses the best practices for acquiring formation pressures with FPWD applied for better understanding of local depletion scenarios. The best procedures were used to obtain accurate reservoir pressure measurements while drilling in a side track section. The pressures were compared with pressure acquired from a WFT in the pilot hole. The comparison was used as a benchmark for the data quality between FPWD and WFT.
Especially with a large scale projects such as new field development planning, it is important to validate FPWD against proven WFT mesurements to ensure data quality is not compromised for cost saving. However, benchmarking two formation testers run at different times with varying mud/drilling conditions needs a good pre-job planning especially if the tolerance is less than 10 psi drift. After consultations with all stakeholders, a logging sequence was agreed upon which optimized logging time, giving the best chance of attaining optimal well-bore conditions for formation testing. Results showed a very good match between WFT acquired in pilot hole and FPWD data acquired two weeks later in the side track section a couple of hours after drilling. The differences between the two measurements were between +0.8 psi and −6.4 psi.