Integration of FPWD Technology to Augment Reservoir Characterization
Authors: Bari Abdul , Zubair Talha , Tanveer Muhammad Sohaib , Zaki Saqib , Jibran Muhammad , Saeed Khizer , Ghouri Saad Ali , Khan Mohammad Rasheed , Nadeem Zunaira , Ashraf Zaid , Hameed Irfan 
Published: January 2024

It has been over a decade since the introduction of formation-pressure-while-drilling (FPWD) technology. Over the years, an exponential rise in utilization of this technology has been experienced, starting from its use in making informed decisions regarding well placement and geosteering, drilling operations enhancement, and reservoir characterization. In this work, FPWD data are integrated with other logs and geological information to create a decision-making toolkit for drilling new wells in two different reservoir structures: complex channel sands and compartmentalized reservoirs. The work demonstrates the efficacy of the information provided by the FPWD tool to augment reservoir management practices.

FPWD technology is used to acquire real-time formation pressures with minimal formation exposure after drilling and is viable in highly deviated trajectories where hole instability issues generally pose challenges with wireline formation testing. An intelligent time-optimized pressure (TOP) test mechanism is employed to extract significant information from heterogeneous formations. This is made possible with the application of a smart algorithm in the FPWD workflow that utilizes mobility values of the investigation pretest to optimize the parameters for the final pretest. As a next step, the FPWD data are combined with sedimentological models to indicate possible locations for drilling new wells in channel sands. Furthermore, in a separate field, geological and log-based models are used with FPWD data to understand reservoir structure, specifically, compartmentalization and fault/seal communication. A well-to-well reservoir characterization workflow is developed based on the information provided by FPWD technology.

The two fields under investigation are in a setting with high temperatures and significant wellbore deviations, in addition to greater sticking risks due to pressure depletion and wellbore-related instability issues. First, deploying FPWD allowed pressure tests to be conducted in as few as 5 minutes depending upon formation properties and relevant TOP setting, thereby significantly reducing operational risks. Second, linking geological and fluid flow information allowed characterizing the channel sands penetrated by the well as virgin or depleted and consequently provided guidance on the channel direction to follow in drilling future wells. Finally, the combination of FPWD and geological data enabled identification of reservoir compartmentalization, fault communication, and three-way closure regimes in wells drilled in the same compartment. As a result, the operator was able to successfully develop and manage the fields by drilling new wells with greater productivity as formation pressure is a necessary measurement to characterize field-level compartmentalization and channel sands and to identify the fluid contacts in a challenging borehole environment. Ultimately, use of FPWD allowed the operator to save rig time as compared to conventional wireline methods.

This work highlights the value that FPWD technology can bring to complex reservoir characterization. The ability to acquire real-time formation pressures (with mud circulation and in pump-off mode) and fluid mobilities using the TOP technique in an optimized time window and safely in an unstable wellbore environment has enabled the operator to better understand the reservoir, identify fluid contacts, save rig time, and improve field management practices. This leads to better and safe well placement and development of an enhanced well-to-well reservoir comprehension.