ABSTRACT

Since the beginning of petroleum industry, drilling engineers have been looking for new techniques which are more efficient, more economical, and safer. Managed Pressure Drilling (MPD) is a new technology which uses tools similar to underbalanced drilling (UBD) and operates by precisely controlling the pressure variations throughout the well.

MPD is mostly used in drilling mature oilfields. In these reservoirs, a series of tight pressure margins are exist in drilling window which makes drilling new wells in the same reservoir extremely difficult. Using conventional drilling methods in such cases can cause many drilling problems due to loss - kick scenario and increasing of Non-Productive Time (NPT) which makes the operation not to be suitable from an economic standpoint. Using MPD technology in mature oilfields would cause NPT to become a minimum.

In this study, application of MPD is considered in Mansouri oilfield which is a mature oilfield in southwest of Iran. In order to evaluate the applicability of MPD in this oilfield, first pore pressure and fracture gradients had been estimated. RFT and sonic log data for 7 wells in this field were used for determining pore pressure and fracture gradients to obtain drilling windows. After obtaining drilling windows, zones in which pore pressure and fracture gradients converge toward each other has been detected. These zones are potential candidates for MPD application.

Results of this work show that Sarvak formation in Mansouri oilfield is a good candidate for MPD practice. This state-of-the-art technology can be used for drilling new wells in this formation by designing most economical drilling programs and more importantly, safest drilling operations.

INTRODUCTION

Since early times in drilling industry, one of the most important goals of any drilling contractor in carrying out drilling projects was to drill safe and economic. The word safe implies a drilling operation that prevents happening of any kick, which can lead to blow out, loss of personnel and money.

This content is only available via PDF.
You can access this article if you purchase or spend a download.