Rervoir drives choice of RSS vs mud motors
t
by rotary steerable tools, however, the friction holds the cuttings in suspen-sion, allowing the fluid to create a vortex around the drill string to provide consis-tent hole-cleaning.绯闻女孩下载
RSS technology also reduces drag, allowing extension in well reach, espe-cially important in horizontal applica-tions. Rotary steerables typically deliver a smooth in-gauge wellbore and control the toolface at the bit, which provides more accurate directional control and less tortuosity. They also enable the u of logging-while-drilling (LWD) azi-muthal nsors to obtain full borehole images.
Applying preci DirectionAl control An important factor in rotary steer-able systems is that they provide pre-ci directional control and are therefore suited to narrow zones as tight as 1 ½ ft. In that regard, the tools also can provide geosteering in the narrow rervoirs, where corrections can be made in real time without sliding.An RSS was ud to successfully drill and complete a ction of a horizontal water-injection well with an 8 ½-in. hole in Abu Dhabi.Using Weatherford ’s Revolution rota-ry steerable system, the operator was able to drill 2,200 ft (671 meters) at a depth of 8,725 to 12,918 ft (2,659 to 3,937 meters) in less than 90 hrs in one run, saving 41 hrs of drilling time and achiev-ing a significant cost savings without nonproductive time.大学英语六级成绩
The same system was ud in another Abu Dhabi water-injection well to facili-tate drilling and completion of an ultra-narrow, 6-ft zone with a 6-in. hole size and a run length of 4,193 ft (1,278 meters).The operator was able to drill almost 20 ft (6 meters) deeper than anticipated, reaching a target that otherwi would have been misd.chinelovelinks
In an onshore Saudi Arabian field prone to lost circulation, differential sticking and hydrogen-sulfide challenges, the same technology drilled a 3°/100-ft (30-meter) dogleg ction with a 6 1/8-in. hole in
an extended-reach horizontal water-injection well to a target depth of 16,856 ft (5,138 meters). Average ROP was 35 ft/hr (11 meters/hr). Prior to deployment of the system, optimal ROP had been difficult to achieve with a steer-able motor asmbly .
The system drilled a total of 7,316 ft
(2,230 meters) in one run, achieving a field run-length record and meeting the operator’s goal to minimize excess trip-ping time. The operation saved 24 hours in drilling time and associated costs and allowed the operator to avoid stuck-pipe and lost-in-hole risks that occur in simi-lar extended-reach wells.In the Bay of Bengal in Eastern India, the same RSS technology performed a record-breaking shoe-to-shoe run in a claystone formation, with interbedded sandstone, marl and calcareous clay . The deep exploratory well had an inclina-tion of 34°. The system drilled a 12 ¼-in. in-gauge hole and then drilled to a mea-sured depth of 4,918 ft (1,499 meters) to improve the average ROP and reduce the number of wiper trips and backreaming. Drilling time was 192 hrs, with an aver-age ROP of 25.6 ft/hr (7.8 meters/hr).RSS technology has been enhanced in recent years by the development of motorized rotary steerable systems,
where a power ction placed on the RSS tool provides additional rpm and torque while still achieving the benefits
of control and eliminated sliding. This
hybrid-type application is increasingly being ud in regions such as the Middle East, where the rock and carbonates are especially hard.
HigH-performAnce AlternAtive五年级数学应用题
Despite its many benefits, rotary steer-able technologies can prent some dis-advantages, including cost, if ud in sit-uations where preci directional control is not the primary objective. For example, to justify the expen of using a rotary steerable system, the savings in rig time and other costs must be greater than the rotary steerable cost.
Rotary steerable drilling performance is delivered from the u of surface rota-tion, making them rig-dependent. They offer limited lection of bit sizes and speeds, and they involve greater com-plexities, both mechanically and electron-
High-performance mud motors can save 50% or more a day over rotary steerable systems. Mud motors also can be ud with smaller rigs that can’t rotate fast enough to enable the rotary steerable mechanism to perform. However, rotary steerables provide greater precision in directional control, an advantage in tight formations.In cas where deploying an
RSS is either cost-prohibitive
or impractical, a high-
performance mud motor can also achieve desired results, provided it is ud in the proper application.”
“
more over an RSS. Lost-in-hole costs also
are significantly lower; a 6 ¾-in. high-
performance mud motor has a typical
lost-in-hole cost of $168,000.
High-performance mud motors can
often out-perform standard, non-motor-
ized RSS, which depend on the rig rotary
table to spin the bit. The motor power
component of the high-performance mud
motor, on the other hand, provides bit
rotation and power directly to the bit.
High-performance mud motors also can
mph
be ud in situations that involve smaller
rigs that can’t rotate fast enough to
enable the rotary steerable mechanism
to perform.
Another benefit is that all bit types
and sizes can be ud with a high-per-
formance mud motor, making it uful
for a variety of applications, including
situations where a particular bit that is
not compatible with an RSS must be run.
High-performance mud motors do,
however, require sliding for directional
线话英语control, which typically reduces ROP.
They offer poor and inconsistent hole-
cleaning and poor hole gauge. Also, LWD
nsors often get pushed back farther
from the bit. Motor bend with high-per-
formance mud motors can limit the drill
string rotary speed or not allow any rota-
tion at all. The factors must be consid-
ered in lecting this method of drilling.
UAe test cAs
High-performance mud motors have
been ud successfully in many deviated
drilling operations and have achieved
better-than-average ROP rates in three
offshore test cas – the Thamama, Hith
and Arab formations in the United Arab乱七八糟的意思
Emirates.
Seven wells in the Thamama Formation
featured multiple target zones and were
characterized by hard, Cretaceous lime-
stone, but they prented no sliding issues.
The operator ud high-performance mud
motors to drill the wells, which were not
horizontal but had deviations ranging
from 0° to 30° and had 8 ½-in. hole sizes.
properties along with diligent analysis
of the well program, including formation,
bit lection, directional program and
other factors, must be considered when
bec中级真题
determining whether an RSS or a high-
performance mud motor will achieve the
best results in terms of cost and effi-
ciency.
In tight or narrow formations where
preci, directional control is needed,
远大前程下载RSS are often the optimal choice for
achieving drilling optimization and
incread ROP. In zones with broader
boundaries, a high-performance mud
motor can provide results at a lower
Revolution rotary steerable system is a trade-
mark of Weatherford.
Scan to watch a video
animation of Weatherford’s
Revolution Rotary Steerable
prevented
System.
