Properly Executed Underbalanced Drilling Technology Adds Reserves and Enhances Ultimate Recovery

Abstract

Abstract The current world petroleum industry situation is that: ➢Exploration is difficult and costs are increasing.➢The majority of hydrocarbons being exploited today are found in existing pressure depleted or complex and lower quality reservoirs➢Current oil prices are at their highest Thus, world circumstances have forced today's petroleum industry to rethink both its operating methods and technologies aiming at improving recovery and reducing cost. It is believed that adoption of new technologies is the most important factor in adding reserves, enhancing recovery, reducing cost and increasing revenue. Underbalanced drilling technology is now seen as the way to achieve these objectives. Introduction Underbalanced Drilling – UBD main objectives are: ➢Preventing formation damage and improving Reservoir Benefits.➢Improving Drilling Performance & Preventing Conventional Drilling Problems. This paper discusses in details the reservoir benefits part of underbalanced drilling technology. What is Underbalanced Drilling? Underbalanced Drilling is the intentional reduction of the drilling fluid density causing the hydrostatic pressure in a well bore to be lower than the pore pressure within a formation thereby permitting reservoir fluids to be produced while drilling. Underbalanced Drilling benefits the reservoir by simply adding reserves through: ➢Discovery of new zones➢Reducing formation damage and increasing intra-zone contribution➢Lowering abandonment increasing well drainage area➢Accessing challenging reservoirs➢Providing real time reservoir evaluation / characterization. Although UBD has many advantages, it is not a magic potion for all fields, wells or drilling problems. Poor execution and planning would result in an over-enthusiastic misapplication of the technology, and possibly failure. Several real results and case studies will be presented and discussed in this paper.