5

5.1 EXAMPLES OF OFFSHORE DEEP DIRECTIONAL DRILLING APPLICATIONS
The BC-10 project has installed an FPSO in some of the deepest waters worldwide. The well configurations include complex 3D profiles that kick off from vertical in a riserless top hole section very close to the seabed in an unconsolidated formation. In the intermediate hole, high turn and build rates are required for accurate landing at challenging targets close to horizontal. The asset is operated by Shell with a 50% interest with joint-venture partners Petrobras (35%) and ONGC (15%)
Complex lithology among interbedded shales, siltstones, and hard limestone layers generated different directional responses that required collaboration by Shell geology/drilling department and the Schlumberger drilling engineering team to gain a better understanding of the directional performance and formation response so that they could plan the correct drilling parameters and improve drilling performance.
Aggressive dog leg severity requirements for the top hole and buildup sections reaching up to 4.2°/100 ft could not be fully met in the initial three wells. For that reason, a change not only in drilling tool technology but also in the planning workflow process was required. Understanding the formation characteristics and anomalies by using seismic modeling software to interpret and extrapolate directional results to the wells being planned had played a key role in correlating formation tendencies with DLS, RSS capabilities, and drilling parameters performance.
The process consists of analyzing actual drilling parameters in the software (ROP, RSS ratio, DLS, drilling parameters) by correlating them with the respective lithology in the trajectory. The results form the basis of the design for planning subsequent sections to be drilled.
Steep performance improvements regarding DLS capabilities and drilling practices under different lithology tendency profiles enabled new benchmarks for technological limits and well complexity. The new technology and process achieved a step change in performance was achieved for surface sections that was proven in 11 sections drilled. Average days per 1,000 m dropped from 8 to 2.5 days for a savings of approximately USD 15 million.
The techniques developed, the directional results of this initial stage of the project, and the lessons learned are discussed. This new techniques has extended the potential of future ultradeep development projects. As a result, the innovative planning process is being considered in the design workflow for similar borehole profiles worldwide.

fig figure 8 drilling through challenging areas. (youtube.com) retrived 20/5/2018

Fig 9 http://www.revolutiondirectionalservices.com. Directional drilling image retrieved 23/5/2018

5.2 NEW DIRECTIONAL DRILLING WITH LINERS SYSTEM ALLOWS LOGGING AND DIRECTIONAL CONTROL WHILE GETTING CASING ACROSS TROUBLE ZONES.

The continuation of profound boring has extended the application for directional boring to close typical extents. Since 1968, there has been a consistent movement of upgrades in profound directional boring devices and systems.
Numerous huge changes in hardware and procedures utilized as a part of directional boring have been made since 1934 when Mr. H. John Eastman was summoned from California by The Humble Petroleum Company concerning their Alexander No. 1 Well at Conroe, Texas. Mr. Eastman proposed an arrangement to begin another well close to the pit and by the utilization of mechanical redirectors would toss it inside a 100′ hover drawn around the base of the runaway well. The consequent arrangement was taken after and the wild well was slaughtered.
Since the introduction of control directional penetrating, progresses in hardware and strategies has proceeded at a quickened rate; by and by, more noteworthy than typical expenses are still connected with directional undertakings. Cost of working bigger apparatuses and ventures. Cost of working bigger apparatuses and giving supporting administrations hatchet expanding and giving supporting administrations hatchet expanding and display no inclination to decrease. As more profound structures are being investigated, the applications have been expanded for profound directional control. Expanded directional penetrating proficiency seems, by all accounts, to be the one means accessible for lessening general cost.
In the previous three years a few profound directional activities have been finished with sensible achievement and cost in the Delaware Basin, Western Oklahoma and the Panhandle of Texas.

KICK OFF POINT PLANNING KICK OFF POINT
All directional wells have or ought to have sufficient wanting to achieve a base opening goal at a predetermined vertical profundity.
A portion of the more natural applications for “profound directional penetrating” in the Delaware bowl, Anadarko bowl and Western Panhandle are to derail rectify an abnormal opening because of rent line issues, divert check, or reentry to increase topographical preferred standpoint by cutting crosswise over flaws or by increasing more structure. Once the target has been characterized, the following thing for thought is the Kick-off point or the profundity at which the directional penetrated segment of the gap is to be begun. It is critical that all variables be precisely considered in choosing the best commence point, regardless of whether it be off base or off a bond plug. The essential contemplations are the measure of edge important to accomplish the coveted deviation, the sort of development and the arrangement structure now.

Experience has demonstrated that directional gaps with 18 degrees least point have a more prominent dependability for holding wanted bearing once the edge and heading has been built up. The most extreme point plan design ought to be more prominent than any development bedding plane edge that will be bored. Subsequently less redirecting apparatus runs are required to rectify the float course.
The mechanical qualities of “profound control openings” for the most part are more hard to control because of the littler gap estimate; along these lines, a specific measure of “elbowroom” ought to be considered in picking the commence point if applications allow.
The continuation of profound boring has extended the application for directional boring to close ordinary extents. Since 1968, there has been an enduring movement of changes in profound directional penetrating devices and systems.
This will feature six distinct sorts of directional penetrating undertakings accentuating the arranging, hardware utilized, systems, arranging, gear utilized, procedures, instrumentation, issues experienced and cost figures related with each kind of occupation.
Numerous critical changes in gear and methods utilized as a part of directional boring have been made since 1934 when Mr. H. John Eastman was summoned from California by The Humble Petroleum Company concerning their Alexander No. 1 Well at Conroe, Texas. Mr. Eastman proposed an arrangement to begin another well close to the pit and by the utilization of mechanical redirectors would toss it inside a 100′ hover drawn around the base of the runaway well. The ensuing arrangement was taken after and the wild well was slaughtered.
Since the introduction of control directional penetrating, propels in hardware and techniques have proceeded at a quickened rate; all things considered, more noteworthy than ordinary expenses are still connected with directional ventures. Cost of working bigger apparatuses and undertakings. Cost of working bigger apparatuses and giving supporting administrations hatchet expanding and giving supporting administrations hatchet expanding and display no inclination to decrease. As more profound structures are being investigated, the applications have been expanded for profound directional control. Expanded directional boring proficiency seems, by all accounts, to be the one means accessible for diminishing general cost.
Arranging KICK OFF POINT PLANNING KICK OFF POINT All directional wells have or ought to have abundant wanting to achieve a base opening goal at a predefined vertical profundity.
A portion of the more commonplace applications for “profound directional boring” in the Delaware bowl, Anadarko bowl and Western Panhandle are to derail rectify an abnormal gap because of rent line issues, divert hindrance, or reentry to increase land advantage by cutting crosswise over issues or by increasing more structure.
Once the target has been characterized, the following thing for thought is the Kick-off point or the profundity at which the directional penetrated segment of the opening is to be begun. It is essential that all variables be deliberately considered in choosing the best commence point, regardless of whether it be off base or off a bond plug. The essential contemplations are the measure of edge important to accomplish the coveted deviation, the sort of arrangement and the development structure now.
Experience has demonstrated that directional gaps with 18 degrees least edge have a more prominent dependability for holding wanted bearing once the point and heading has been built up. The most extreme edge plan design ought to be more noteworthy than any arrangement bedding plane point that will be penetrated. Thus less diverting apparatus runs are required to rectify the float heading.

The mechanical qualities of “profound control openings” for the most part are more hard to control because of the littler gap measure; hence, a specific measure of “elbowroom” ought to be considered in picking the commence point if applications allow.