Case study: Middle East

Integrated Well Services performs
record-setting UBD, CTD operations,triples average production rate
In 2009, an operator in the Middle Eastneeded to develop a series of coiled
tubing drilling (CTD) operations in aformation laced with highly deviatedand horizontal laterals to achieve
maximum reservoir contact (MRC).
When the project began in thisformation with low porosity andpermeability, the typical drillingpressure was around 3,000 psi(20.6 MPa). Downhole temperatures
averaged 302°F (150°C) while thehydrogen sulfide (H2S) content sat at
6%. With a thin net pay layer averaging<10 ft (3 m), any solution would have toaccount for all these factors.

Aligning the well plan
The operator contracted Baker Hughes
for two years to provide CTD andunderbalanced drilling (UBD)
operations in the gas re-entry
program. The scope called for Baker
Hughes to drill nine wells per year perrig. The Baker Hughes Integrated Well
Services (IWS) team studied thechallenges presented by theoperator’s requirements and thelimitations of the formation.
Combining project management
expertise, a comprehensive
technology portfolio, and superior
service delivery, IWS collaborated withthe operator to optimize project
performance and value.

Designing the solution
The complete package Baker Hughesdelivered encompassed a broad
range of services including directional

drilling, formation evaluation, wellsite
supervision, and pressure pumping,but the core of the project deliverables
was project management and wellengineering. Through close
collaboration with the operator, theIWS team ensured all aspects of theproject aligned with the agreed upon
objectives and selected thetechnologies for deployment.
The CoilTrak™ CTD bottomholeassembly (BHA) system would be
used for the coiled tubing operations.
This system increases recovery rates
and improves well performance inslimhole directional CTD applications.
For the duration of the project, the IWS
team recommended the Baker Hughes
Dynamus™ extended-life drill bits.
These bits reduced trips while
preventing damage that shortens thelife of sensitive BHA components bysmoothing out lateral vibrations.
The Delta™ exit system enabled theoperator to mill a window in a
restricted wellbore environment using
coiled tubing deployed mills andmotors. The Delta exit system can be
run and set in a live well environment
without the necessity of removing thecompletion equipment, eliminating therequirement for a workover rig andnegating the need for kill weight fluids.

Challenges• Highly deviated horizontal laterals• Thin net pay layer averaging<10 ft (3 m)• Low permeability and porosity• High-temperature sour wellResults• Re-entered more than 200 wells(>600 lateral), exceeding 1.4 million ft(425 000 m)• Improved production acrossthree fieldsoField 1: 403%

oField 2: 393%

oField 3: 269%

• Increased annual well delivery
by 53%• Reduced the average days per wellfrom 38 to 26 days
• Decreased NPT each year to a totalof a 77% reduction• Went 8 years with zero LTI

Underbalanced coiled tubing drilling(UBCTD) was introduced as anenabling technology to accelerate andincrease gas recovery at a rate
greater than conventional technology
can deliver.

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Executing with predictableperformance
Baker Hughes engineers and field
personnel began implementing thetwo-year well plan in the second halfof 2010 with a single underbalanced
CTD package. Since that time, theproject has expanded to multiple
service providers, operating four coiled
tubing drilling units for the operator.
By aligning all aspects of theoperation, Baker Hughes and theoperator re-entered and drilled morethan 200 wells, surpassing 1.4 million ft
drilled (425 000 m). The Baker Hughes
IWS team consistently exceeded theoperator’s expectations and set
significant record-breaking
achievements including, in 2016,delivering wells 62% faster thanconventional methods within thesame field.
From the success of the project’s initialstage, the operator now targets wellswith higher temperatures—>350°F(>177°C)—with sour gas concentrations
ranging from <1% to ± 10%.

Baker Hughes technology kept pacewith the operator’s objectives. At theoperator’s request, engineersdeveloped the CoilTrak™ HT CTD BHA
system. Specially designed for hightemperature (HT) re-entry drilling, theBHA delivered reliable drilling
performance in this type offormation and in temperatures up
to 347°F (175°C).
Additionally, Baker Hughes experts
optimized the drill bit technology tomeet new project objectives byintroducing the Dynamus™ extendedlife drill bits. These cutters aredesigned to prevent prematurecracking and wear while offering anew, high-strength body engineeredfor extended life in extreme operations.

UBCTD technology was expanded
throughout the field, and has recently
been deployed to drill a reservoir
section in underground gas
storage reservoirs.
The initial two-year contract included
an option for a one-year extension, anoption that kept being renewed forover a decade. The predictableperformance of the Baker Hughes
solution consistently exceeded theoperator’s expectations and, as ofQuarter 2 of 2021, Baker Hughes
remains the service provider of choicefor the operator.

The target bottomhole circulatingpressure has decreased over time,increasing the benefits to drill at lower
pressures despite the thin pay zone.

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