Abstract
The first highly deviated Deep Water well with an inclination up to 80° was drilled in Mexico. A strategy developed in collaboration with the owner and Directional Drilling contractor allowed to safely drill the well within AFE and reach all planned objectives.
In order to maximize production, avoid geological risks and optimize utilization of existing subsea infrastructure the Deep Water well (with water depth over 3000ft) was designed with inclination reaching 75°, demanding dog leg severity (2.5°/100ft) and several sections to be enlarged while drilling.
Being the first well with such high angle in Mexican Deep Water, Lakach-52 did not have much of a reference. Many design and operational issues had to be solved for the first time.
Besides problems typical for highly deviated wells, such as hole cleaning, wellbore stability, high ECD, etc., potential issues were anticipated with a kick off from vertical in very soft formation, perform directional work within interbedded formations and a zone of conglomerates, pass between faults and simultaneously enlarge the hole.
Additionally, a number of factors were taken into account in order to design the well: existing subsea infrastructure, local practices, geological/geomechanical risks, operational risks (direction, S&V, stuck pipe, etc.)
In order to ensure flawless performance and address all potential issues, the service company ran the project under integrated management roof. A special communication protocol/structure was designed in order to optimize the decision making process than response time. A specific project drilling strategy was developed for each stage of the well construction process.
All BHAs as well as drilling parameters were designed using the following approach: fit to purpose BHA tendency, bending stresses below critical, minimum shocks and vibrations and optimized hydraulics.
As a result, the well was successfully drilled within AFE curve, all given targets were successfully achieved. All sections were drilled with ROP faster than planned. The conductor was jetted and the following section was drilled ahead using a straight motor with a minimum deviation from verticality 0.26° The kick off successfully performed at very shallow depth and very soft formation with push the bit Rotary Steerable system. The 17 ½" × 20" section was drilled successfully in 1 run. Inclination was built to 30°. The 14 ½"x 17 ½" section was the most challenging section. 3 BHAs were used to drill the section. Optimization of the BHA allowed to eliminate shocks & vibrations and reach drilling objective within the given tolerance, despite the geological complications and demanding well profile. The 12 ¼" section was drilled successfully to TD and the required LWD logs were obtained in the reservoir at 75° of inclination.
