Following the numerous successful applications of the Lean Profile (LP) concept, a further step towards production maximization, with simultaneous increase of operational safety and reduction of the overall drilling time and cost, has been achieved with the introduction of the Extreme Lean Profile (x-lp).
The case history outlined in this paper can be deemed as one of the most successful application of the x-lp technique, since it has allowed the accomplishment of an outstanding production performance in a mature field, where, for the first time, the reservoir target has been reached with a horizontal 8 ½" hole section within naturally fractured carbonate formations.
Despite the challenging geological and environmental conditions, the use of x-lp technique has proven to make the difference in achieving operational excellence.
A distinctive feature of the x-lp is the reduced clearance between casing and wellbore, enabled by the use of automatic drilling tools which allows to obtain a good hole quality in terms of smoothness and absence of micro-tortuosity, resulting also in an improved effectiveness of cement bond.
The x-lp makes available two additional casing strings compared to a conventional casing profile, which can be used to reach deeper targets or as a contingency for well construction in critical drilling conditions, or, as in the case described herein, to maximize the well productivity by reaching the reservoir with a production hole diameter larger than offset wells in the field.
This paper provides a comprehensive description of well requirements, the associated operational issues, the chosen solutions and the achieved results. It also provides an overall description of the x-lp technique, its most important features and advantages in terms of cost reduction, minimization of environmental impact and enhancement of drilling performance.
