Cemented ball-drop sleeves enable
operators to reduce cost and operational risk, while helping achieve optimal
pumping rates to improve production potential in extended-reach laterals.
MIKE KENYON, Packers Plus Energy
The price of oil
experienced a recovery from fourth-quarter 2020 forward, amid the Covid
pandemic, and in 2022, WTI eclipsed the $100/bbl mark for the first time since
2014. But with the price hovering around $80/bbl since November 2022, producers
are reminded of the volatile nature of commodity prices and the need to
continuously focus on reducing lift costs.
For completion programs,
that means reducing the costs of frac operations, while still delivering an
effective treatment along the entire lateral of a horizontal well to maximize
production potential. The common trends for all well designs are a move to:
There are several
completion methodologies being deployed across the Canadian market—as geology
changes, so does the optimal stimulation technique. Frac rates range from 1-14
m3 per minute with varying sand concentrations and tonnages per
CEMENTED BALL DROP SYSTEMS
Increasingly, we are
seeing producers deploy cemented ball-drop completions for either the toe
stages as part of a hybrid completion or the entire wellbore, Fig. 1. By
moving away from plug-and-perf or coiled tubing sleeves, producers can complete
fracs quicker, increase frac rates and reduce required post-frac operations,
which will lower cost and improve production potential. Packers Plus has two
options for cemented ball-drop sleeves, Fig. 2:
In addition, other key
technologies that make up an effective extended-reach lateral completion
The next section will
explore new completion trends and highlight how cemented ball-drop technologies
can help operators improve the effectiveness of their stimulation programs and
maximize the production potential of every well.
Extended-reach laterals. Over the last 10 years,
the number of horizontal wells completed with lateral lengths exceeding 3,000 m,
in unconventional plays across North America, has grown significantly. And
longer laterals mean more stages. Single-digit stage counts from the early days
of multi-stage stimulation at the turn of the century have given way to
50-stage jobs commonly being pumped, and wells with more than 100 stages are
becoming more frequent.
weight-on-bit to mill out frac plugs post-stimulation or generating enough
weight to shift coiled tubing sliding sleeves are two challenges that can arise
when completing extended-reach laterals. Combining a hydraulically activated
toe sub with sliding sleeve technology in the lower stages of an extended-reach
lateral well can further enhance the operational efficiency experienced for the
Ball-activated sleeves transformed
well completions through continuous pumping operations. The benefits of reduced
time and cost associated with continuous pumping operations in single-point
entry ball-activated sliding sleeves were soon adapted to allow one ball to
open multiple sleeves in a stage—mimicking the limited-entry treatment of
plug-and-perf. These systems were soon developed further to work in cemented
sleeves allow the operator to pump the frac continuously, eliminating down time
and reducing fluid requirements when compared to plug-and-perf. To complement
the reduced operational time during stimulation, SF903 dissolvable balls were
developed to eliminate the need to drill-out post frac.
High-rate stimulations. The trend toward pumping stimulation treatments
at higher rates, with high fluid volumes, higher proppant loads, tighter stage spacing,
and higher stage counts, has contributed to better operational efficiency and
However, the same proppant that improves
production—especially at high volumes—can also erode downhole tools to the
point of failure, resulting in expensive remedial solutions or lower production
and potentially both.
completions, proppant eroding and enlarging perforations cause the first
cluster to accept most of the fluid, while others in the same interval receive
minimal or no treatment. Production logging also has shown that only 20% to 50%
of the intended fracturing targets in a perforation cluster were producing at
fracture-stimulated rates. This inefficient use of proppant leads to lower-than-expected
production and reduced return on investment.
In ball-activated sliding
sleeve systems, the turbulence of fluid flow through a seat causes a slight
pressure increase. This is inconsequential for one seat, but a completion
string of 40 to 50 sliding sleeves can add thousands of pounds of pressure in
additional friction, which is a source of operational concern. Fortunately,
these issues have been mitigated specifically for both single-point and
limited-entry completions by reducing fluid friction, and mitigating ball/seat
and entry point erosion.
Packers Plus sliding
sleeves were re-engineered to mitigate cumulative fluid friction. Using
computational fluid dynamics simulation, the reshaping of the internal fluid
path reduced pressure drop (and thus fluid friction) by over 60%. These design
enhancements to the Diffusor Sleeves and QuickPORT IV Sleeves, combined with
Packers Plus Inner Armor erosion coating, ensures completion equipment
integrity during high-rate/tonnage stimulation.
The diffusor sleeves also
incorporate Packers Plus’ StackFRAC HD-X ball seats. These ball seats come in
increments as low as 1/64-in., which enable the delivery of high intensity
stimulation treatments with rates as high as 16 m3/min and 200
tonnes of sand per stage. A high rate can even be achieved at the toes of the
wells, where the smallest seat size is typically no smaller than 2-in.
The nozzles on the
QuickPORT IV sleeves are reinforced with tungsten carbide, which virtually
eliminates erosion of the entry point during stimulation, while the offset
spacing of the nozzles facilitates even distribution of the treatment across
the entry points.
QUICKPORT IV OVERVIEW
QuickPORT IV sleeve is a ball-actuated, hydraulically activated
injection/production port used with the Packers Plus limited entry system. The
sleeve allows for more than one stage to be activated with the same size
actuation ball for limited entry stimulation. There is a variety of ball sizes
available, allowing for multiple stimulation treatments to be run in sequence.
QuickPORT IV sleeve flow ports are available in a variety of sizes to optimize
the limited entry stimulation treatment. After stimulation, the well can be
immediately put on production and if desired, the ball seats can be milled out,
based on the operator’s completion requirements, Fig. 3.
QuickPORT IV sleeve is assembled in the completion tool string, according to
well requirements and run into the wellbore to the planned depth. The
appropriate ball size is inserted into the string and pumped down to the
uppermost sleeve in the limited entry treatment zone. The tool string is then
pressured up, and the sleeve is shifted open. The ball then passes through the
sleeve and continues down the liner to activate other QuickPORT IV sleeves
within the treatment zone.
the QuickPORT IV sleeves are opened, the designed stimulation rate can be
achieved. Each subsequent zone is treated, using an incrementally larger ball
to activate the sleeves. The larger ball size also isolates lower zones from
the up-hole pumping operations. After stimulation, the ball seat can be milled
out, if desired.
Diffusor sleeves in a full wellbore. An
operator in central Alberta planned to complete three wells with high-rate slickwater
stimulations. The wells were not on a pad, so the efficiencies of plug-and-perf
operations were not an option. The liners were deployed on drill pipe and
cemented in place below a Packers Plus PrimeSET liner hanger. Stage 1 was stimulated
through the Packers Plus Toe AP hydraulic port, and the remainder of the stages
were stimulated with diffusor sleeves (35,38 and 55 stages), Fig. 4.
were launched at full frac rate and 10 m3 per minute was maintained
until 5 m3 prior to landing the ball, when the rate was slowed to 2 m3
per minute until the port had shifted. Acid pumped immediately behind the ball
helped with formation breakdown, and the operator was able to increase rate
quickly and begin the frac. This procedure reduces fluid volume requirements
and increases the speed of operation. Frac parameters were as follow:
this case, all stages were stimulated successfully, and wells were put on
Diffusor sleeves overcome deformation
issues. An operator experienced casing deformation challenges during
both coil frac sleeve and plug-and-perf operations. Cemented ball drop sleeves
were trialed on a three-well pad, and all stages were stimulated successfully. The
plug-and-perf operations also had complications when trying to achieve
breakdown. With the ball drop system, the ball can be launched and followed immediately
by acid, allowing for immediate breakdown. The operator continued to run four
wells on a pad, averaging 55 stages of cemented ball drop over a 3,300-m lateral
length with 60-m spacing. The liners are deployed on drill pipe, and the
PrimeSET liner hanger is set in the intermediate casing after cementing.
initiated through Packers Plus Toe AP ports for stage 1. The remainder of the
stages were ball-activated, and all launch and shift events were verified by
the Packers Plus ePLUS Retina monitoring system. After stimulation, the wells were
put on production with no drill-out required (dissolvable balls).
80-Sleeve QuickPORT IV hybrid well. An operator successfully
resolved operational issues in extended-reach laterals by deploying
ball-activated sliding sleeves for the toe stages of their plug-and-perf
completions. This hybrid completion technique deployed QuickPORT IV sleeves in four-sleeve
clusters for the first 20 stages of the well.
The operator had been
using plug-and-perf operations but experienced issues with wireline and coiled
tubing for plug setting, perforating and providing sufficient weight-on-bit for
mill-outs in wells with a measured depth (MD) greater than 6,096 m. The operator
began running QPIV sleeves on all wells beyond this point, placing one port per
joint. They evolved to wells up to 7,102 m, MD, with lateral sections of 3,719
A total of 80 QuickPORT IV
sleeves, run in four-sleeve clusters, were designed to cover the first 20
stages of the well and the deepest 1,189 m of the lateral. The rest of the well
would be completed, using plug-and-perf. All 20 stages were stimulated in under
70 hrs of pumping time, during which the ePLUS Retina monitoring system
verified the launching of balls and actuation of the sleeves. The success of
this completion proves the effectiveness of the QuickPORT IV sleeves, not only
in reducing operational risk for interventions at the toe and saving the cost
associated with downtime, but in its ability to perform as a high-stage-count
12-sleeve diffusor set-up deployed in
a hybrid wellbore. Using coil frac sleeves, an operator in the Charlie Lake formation
evolved to longer lateral lengths beyond the reach of coiled tubing. Coiled
tubing could reach to 6,500 m, MD, on a 2,300-m TVD well, but the operator
planned to drill to 7,350 m, MD.
12 stages of diffusor sleeves. The 12 stages were stimulated
with ball drop, and the remaining 59 stages with coiled tubing over an 850-m
section. The 12-stage ball drop section stimulated well below maximum pressure
at the designed frac rate. Higher rates can be achieved without the coiled
tubing in the hole, and no drill-out was required. The smallest seat in this
case was 76.2 mm, ID. The operator has deployed several systems in this manner
and has more planned, which will reach further depths in the near future.
During the past two decades,
as operators continued to develop new fields, maximize recovery and increase
stage counts and treatment sizes, completion technology has evolved
continuously to meet the needs of operators.
Sliding sleeve technology
helped transform the completions industry nearly two decades ago, and
innovation has continued steadily throughout the years to help maximize
efficiency. From single-point entry sliding sleeves to hydraulically activated
toe sleeves and limited-entry cemented ball-drop completions, each evolution
has played a role in advancing completion capabilities by enabling treatment of
longer laterals and more stages with more proppant and fluid at high rates, Fig.
variations and options provide producers with flexibility in developing their
particular geology and take into account completion trends, such as extended-reach
laterals and high-rate stimulation that provide the potential for increased
production at a lower cost.
With a reputation as the
premier ball-drop completion system provider and more than 250,000 stages
completed worldwide, Packers Plus has expanded its offerings in recent years to
include innovative technologies for a variety of applications and multiple segments
of a well completion. The common theme among all these product portfolio
additions is they are designed to help producers improve operational
efficiency, reduce risk and improve completion programs. Learn more
about the company and its advanced multi-stage completion system technology at https://packersplus.com/en WO
is regional sales manager of Canadian Operations for Packers Plus Energy
Services. He has 25 years of oil and gas experience and has been involved in
running and designing open-hole multi-stage systems since their inception. Over
his career, Mr. Kenyon has also worked in various operational and sales roles.