Kra Al-Maru 3 (KM-3) is a deep vertical exploration well originally drilled to investigate the hydrocarbon potential of the Jurassic formations. Investigation of the open hole logs/cores indicated that there was limited porosity development in the Marrat zones of interest. Therefore an operational opportunity became available to deepen the well to explore the deeper Triassic horizons which had gas bearing potential.

The main challenges of this well were to design an extended casing program within the constraints of the present wellbore to allow for drilling/testing of the well with a wellhead rating of 20,000 psi whilst assuring the collection of maximum amount of useable data (cores, logs, rates, pressures and samples).

In order to meet these challenges a special casing design was employed, based on the experiences of other deep wells. Special HPHT cement additives were specified for the cementing of the deep liner strings. Application of turbine and slim hole motor technology was tried and a HPHT well test operation was planned including the use of a state of the art 20,000 psi surface test package.

During the well re-entry major complications were encountered due to high pressure profile, high mud weights, severe losses and well control situations. During the initial short term test the well produced gas, condensate/light oil along with highly saline water which caused salt plugging of tubing and surface lines. Plans are in hand to re-enter the well for long term test after solving the problem of salt plugging.

This paper will present a case history of the well including the planning, design process, implementation and lessons learned from the drilling and testing operations. These conclusions will then provide the basis for future optimization in the design of these types of wells.

You can access this article if you purchase or spend a download.