The Abu Dhabi Company for Onshore Oil Operations (ADCO) operates a number of onshore fields in the emirate of Abu Dhabi in the United Arab Emirates. ADCO is a performance driven organization. As part of its Well Delivery Limit initiative, the company has focused on the technology enablers, and rotary steerables were seen to be one of the key technologies in delivering performance improvement.
The majority of the wells drilled in ADCO's fields include a horizontal lateral section through the reservoir. Therefore most wells require directional drilling technology and, in the past, have been drilled with conventional steerable mud motor assemblies. Due to the nature of the formations through the build and tangent sections and in order to provide directional control in the laterals, considerable orientated drilling has been required. Oriented drilling has proved to be time consuming and would often result in poor borehole quality. In order to minimize the effect of these issues and to optimize the overall drilling process, various types of rotary steerable systems have been used in a number of wells over the past year.
This paper will review the use of one of these systems. It is based on ‘point-the-bit’ and extended-gauge bit technology. The principle of the tool's design and its operational features will be discussed. In addition, selected case histories from ADCO wells will demonstrate the tool's ability to kick-off from vertical, build a smooth curve through the normally troublesome massive Nar Umhr shale sequence, and then geosteer through the horizontal section. Improvements in overall hole quality, and the benefits this brings, will be described.