Shayegi, Sara (Shell) | Kabir, C. Shah (Hess Corporation) | If, Flemming (Hess Corporation) | Christensen, Soren (Hess Corporation) | Ken, Kosco (Hess Corporation) | Casasus-Bribian, Jaime (Hess Corporation) | Hasan, ABM K. (Hess Corporation) | Moos, Daniel (Dong E&P)
Underbalanced drilling (UBD) offers a unique opportunity to estimate undamaged, in-situ formation properties upon first contact with the formation while drilling. This paper compares well-testing techniques developed for UBD with conventional methods. The reservoir flow rates in combination with flowing bottomhole pressures (BHPs) acquired while drilling can be used to identify productive intervals and estimate dynamic reservoir properties.
Unlike typical UBD projects where reservoir benefits are the primary focus, the driver for this mature field was overcoming the drilling problems associated with the wide reservoir-pressure variability caused by nearby producers and injectors. UBD was piloted as a means to achieving the requisite lateral lengths for reserves capture and meeting production targets. Minimizing formation damage and characterizing the reservoir while drilling were added benefits.
Several reservoir-characterization methods based on rate-transient analysis (RTA) were used to perform well testing while drilling. Rate-integral-productivity-index (RIPI) analysis uses the rate and pressure data acquired during drilling to determine whether additional holes drilled contribute and to ascertain the relative quality of this rock. In the increasing-boundary method, real-time rate and pressure data during drilling, circulating, and tripping allowed assessment of formation properties through history matching. Pressure-buildup data were also available during trips because the concentric annuli allowed the pressure to be monitored below the downhole isolation valve. These data enabled the estimation of reservoir pressure and productivity index (PI) with a proxy vertical-well model for each productive interval drilled. These interpretation methods show close agreement in results and lend credence to the UBD-derived parameters.
The Danish energy utility DONG Energy is one of Northern Europe's leading energy groups. The business is based on procuring, producing, distributing, trading and selling energy and related products in Northern Europe. One of the core business units, DONG Exploration & Production (DONG E&P) explores for and produces offshore oil and gas.
The present paper describes the DONG E&P 1st, 2nd and 3rd Line set-up for emergency preparedness and response, the planning process carried out, the human resource development needed and the lessons learned, when upgrading the 2nd Line onshore emergency response set-up from a traditional emergency room white board approach to a web-based crisis management program system with 4 electronic information boards.
A computer based set-up linked with an internet web-server program for 2nd Line on-shore crisis management has shown to offer a number of advantages compared to a traditional white board based system. Information and allocated actions are much more easily accessed, transferred to and shared between the involved duty functions. This allows staff on other locations to be directly involved in the emergency response team actions. As the system is web-based, the information boards and the crisis management system can be accessed from anywhere (including 1st and 3rd Line) as long as one has the appropriate user rights. The system has a log-function very useful for event documentation and training purposes - as well as a roster planning module.