Increased sand production in existing wells remains a challenge that forces
operators to perform corrective work. An intervention-based remedial sand
control system can be installed through tubing and combine sand clean-out as
part of the installation process. Once installed, the tool requires no further
intervention and is easily retrievable.
EILIDH MCKAY, NICOLA WIGG, KEITH PARROTT, Tendeka; and BAIDA IQLIMA,
Pertamina Hulu Mahakam
Sand control challenges can occur over the life of the well, from
initial completion design to failure of existing downhole equipment, or in
later life, due to increased water production. Regaining sand control integrity
in existing completions is now a more pertinent issue to overcome. In cased and
perforated completions, careful consideration needs to be given to either
installing sand control products in the early stage of the well or,
alternatively, incorporating the option later.
New sand control technology. To address integrity problems, a new-generation
sand control technology has been developed by Tendeka, a TAQA company. Filtrex,
a through-tubing remedial solution, boasts a unique filter mechanism comprised
of a conformable open-cell matrix polymer (OCMP), Fig. 1. It was
recently deployed across a three-well campaign in the shallow waters of Mahakam
field, Indonesia, for PT Pertamina Hulu Mahakam, which had been experiencing
numerous sand control issues, mainly, erosion, pass-through and plugging. Overall,
the OCMP filter had a positive effect on sand retention and delivered improved
well performance. Following on from the well campaign, the technology is
undergoing further improvements for use in gas wells requiring sand control that
expected early water breakthrough.
Novel through-tubing remedial solution. Using similar
sizing to the predicted sand generation in the field, the aim of the laboratory
and field evaluation was to assess the suitability and performance of the OCMP
filter, using both outcrop and reservoir sands, Fig. 2. The OCMP filter was
selected as an alternative to a mechanical screen, to address pass-through and
plugging challenges, due to improper screen slot opening size and high
uniformity coefficient (UC).
The OCMP is a multi-layer design, with up to 85% porosity and 43.4 Darcy
permeability. The technology is run-in-hole, compressed within a sleeve via
coiled tubing or slickline, where it can be deployed along with an integral
anchor system or latched into retrievable set packers. Once set, the filter
media will return to natural shape and size to conform with varying wellbore IDs.
This allows transit in tight restrictions within the upper completion whilst
also setting and conforming to larger casing/screen IDs, where control of sand
has been lost. The OCMP filter conformance completely fills the annular gap,
preventing further solids ingress into the wellbore, thereby reducing the
impact of any potential further erosion and plugging failures.1
As there is no change to the OCMP once deployed, the pore size and shape
are known prior to deployment, enabling an accurate understanding of its performance
in well environments. With a range of sizes to cover a broad range of
applications, once installed, the tool requires no further intervention but can
be retrieved easily later, if desired.
During deployment, a compression sleeve completely protects and
compresses the OCMP until at depth, when the sleeve is removed. After removal
of the sleeve, the OCMP expands and conforms back to its initial size and
shape. As the tool can self-centralize, it can be used in high-deviation wells.
The OCMP is adhered to an optimized base pipe, which is not limited to standard
API base pipe sizing. The base pipe, itself, is designed specifically to
support the OCMP in high-rate environments.
Operator challenge and methodology. The strategy of Mahakam field is to produce
from shallower intervals in unconsolidated formations, in both oil and gas
reservoirs that have a limited producing life.2 Therefore, embedding
a sound sand control approach is paramount. Pass-through and plugging were
common challenges in the field, related to the particle size distribution (PSD).
So far, there was no established screen that could tackle sand issues related
to the PSD dependencies. Meanwhile, erosion was caused by the high production
rate. Conventional sand consolidation treatments, such as through-tubing
screens and gravel packs, as well as erosion-resistant screens, had been
installed with varying success.
Three wells were assigned for sand control intervention. All three wells
(two were from different fields) had the same well architecture, 3.5-in. 9.2#
(2.992-in. ID) cemented monobore perforated casing completion, with a minimum
restriction of 2.81-in. ID. Due to the short lifespan of the production
intervals—between three and six months—it was critical to recover as much oil
or gas before the zones watered out and with the lowest skin possible. The
target of the OCMP was to provide sand control integrity beyond the duration of
other solutions previously implemented.
During retention tests in the laboratory, the prepared formation sand
slurry is pumped and diluted with water before being flowed through the
compressed OCMP filter. Pressures are then recorded over time to monitor
pressure build-up to indicate whether the OCMP filter is providing adequate
retention and/or is liable to plugging during the trial.
The effluent samples collected were filtered through pre-weighed 1.2μm
filter membranes, which were dried and then reweighed. The pressure data and
sand-through data results were collated and represented graphically for
interpretation alongside image analysis of the grains passing the filter. Most
of the sands were sorted with D10 values c.250-300 microns. However, there were
other challenging exceptions including poorly sorted and bi-modal
Both outcrop and reservoir sands were chosen to represent the PSD across
the data provided, covering a range of particle size distributions that could
be encountered within the targeted wells. There were two outcrop sands (sand
mix 4 and mix 5): the first was poorly sorted sand with a high fines content, while
the other well was sorted with a lesser D10 value and fines content. The
reservoir sample chosen was very poorly sorted and had fines with >30%
grains less than 45 microns. The PSD of the sands was measured by dry sieve
OCMP sand retention results. In line with manufacturing and operational
requirements, the OCMP filter was compressed to achieve optimum sand control
effects. During this evaluation, the sand-through retention tests performed were
low, and the sands were very well-retained. To further qualify the retention
performance of the OCMP filter, a comparison was made of the change in sand-through
with time and the pressure profile. In essence, sand control is achieved, if
the sand-through data quickly drop to a low level during the test. If control
is poor, then significant amounts of sand will continue to be produced during the
test. The pressure drop observed will be a combination of the sand permeability
and any plugging of the OCMP filter—the filters themselves are too permeable to
generate any significant pressure drop.
Therefore, the pressure profiles for a particular sand should be similar
on each polymer filter, given good retention and no plugging. At the end of the
retention test, sand injection is stopped to perform a swab-and-surge-style
test to help identify any plugging with the filter. The flow of clean water is
started and stopped at regular intervals, and the pressure is observed for any
inconsistencies. Figures 3-5 show data obtained using the test sands,
which demonstrated good results.
More sand passes through the filter initially with sand mix 4 and fine
reservoir sand, due to the higher percentage of finer material but it falls
away to lower levels in line with the other test sand (sand mix 5). The
pressure profiles recorded during testing also confirmed this. The low and
steady pressure profile generated by sand mix 5 is due to the sand permeability
and lower level of fines (2.6%). There was no evidence of plugging during the
tests, and good retention was achieved in each case. Sand-through, with time,
demonstrated good overall retention performance, while pressure data were
stable and matched the sand properties. There was no evidence to suggest that
any plugging occurred with the sand tested.
However, it should be noted that while plugging can occur with any OCMP
filter combination, there is still insufficient information to determine any
specific criteria for a plugging risk to occur. The evaluation concluded that
the OCMP filter had a positive effect on sand retention and delivered improved
Further examination. Retention tests examine overall trends with
OCMP filter performance. The total sand-through in each test can be used to
examine whether any correlation exists between a sand size parameter and sand
retention by a given filter medium. The polymer filters being evaluated were
depth filters, and so retention may be expected to correlate to the sand D50 value,
as with gravel packs, rather than D10, as with metal mesh surface filters. It
is important to note that gravel packs have largely mono-sized pores, whereas
polymer filters have a range of pore sizes, and so different parameters are
relevant in this case. Polymer filters were tested to give an indication of
sand distribution at the end of the test.
It was not possible to definitively determine retention criteria from
the data available in the initial developmental phase of the OCMP. However,
based on results collected thus far, if the sand is large enough to be retained
(as judged by the D50 value) then the amount of sand passing the polymer filter
correlates to the fines content. When the concentration of fines is higher,
compression of the OCMP creates a significant change to the retention
As a result of conducting laboratory testing with single and multiple
PPI filter combinations and compressing the material, which included an
additional convergence layer, Tendeka repeatedly improved the performance and
understanding of the downhole filter mechanism in new and challenging remedial
environments, with both outcrop and reservoir sands.
Operational deployment. The Filtrex system was initially designed to
be deployed, using coiled tubing. However, most through-tubing sand screen
installations in Mahakam field are transported by slickline. Thus, a slickline
version of the tool was developed. A packer was first pre-set at the
pre-determined depth, using a casing-collar locator correlation below the OCMP
filter to function as the anchoring system. The OCMP sand screen then latches
into this packer. As soon as the tool has been latched and anchored, the running
tool is functioned to release. Force and jarring are then applied to pull off
and retrieve the compression sleeve and expose the OCMP filter. As no top
packer is required on the three wells (Ax-1, Ax-2 and Ax-3), the perforation
interval was designed so that the OCMP filter would have 1-2 ft of overlap, as
shown in Fig. 6.
Results of technology deployment. Oil-producing well Ax-1 was identified as
having a high risk of sand production and had an output target of 150 bopd.
After deployment, the well test showed it was producing 600 bopd, sand-free.
And within a five-month period, the recovery factor was up 155%.
Gas-producing wells Ax-2 and Ax-3, with deviations up to 58°, were then completed.
Initial well test results showed production at 2.55 MMcfgd, sand-free. The
target rate was 1 MMcfgd. Therefore, the tool exceeded expectations and
outperformed results experienced with sand control treatments in similar wells.
However, due to water breakthrough at 2.5 MMcfgd, after one month, both wells started
to produce some sand.
After two months, well Ax-3 had recovery at 300% and was still producing
sand-free at a lower rate of 1 MMcfgd. However, it was suspected to have a
higher shale content than the other two wells, resulting in lower wellhead
flowing pressure and is no longer producing. All wells were shown to have exceptionally
low skin-aiding production. This was an unknown prior to the well campaign.
Due to the campaign’s success, the operator is planning to use the OCMP
sand control tool as its primary sand control system in both cased and
perforated reservoirs, eliminating the requirement to stock various micron-sized
screens and gravel. The results of the three-well campaign have shown Filtrex
has a high potential to outperform most of the developed sand control
technologies utilized in Mahakam field. WO
This article is an abridged version of
“Advancements in remedial sand control solutions - successful deployment in
three well campaign,” SPE paper 213642-MS presented at the Middle East Oil, Gas
and Geosciences Show, Manama, Bahrain, February 19-21, 2023.
EILIDH MCKAY is a technical support manager at Tendeka, a
TAQA company. Ms. McKay holds a Master of Science degree in oil and gas
engineering and manages Tendeka’s application engineers, operations and subsurface
teams. She is one of the inventors of the Filtrex sand control solution.
NICOLA WIGG is laboratory team lead at Tendeka, a TAQA company. She has extensive
experience in the energy sector, with a proven history in sand control,
laboratory operations and completion technologies. Ms. Wigg also has a strong
background in engineering, holding a Bachelor of Science degree with a
specialization in geology/petroleum geology from the University of Aberdeen.
KEITH PARROTT joined Tendeka in August 2018. He has more
than 30 years of experience in sales, operations and project management of oilfield
completions systems, sand control and intervention. Prior to Tendeka, he held various positions within Otis and
Halliburton, and spent 20 years with Weatherford, working in the UK, Malaysia
and South Africa where he was region completions manager before returning to
Malaysia to run the lower completion business. Mr. Parrott has a strong
technical and sales background as well as demonstrated leadership skills to
support Tendeka’s APAC region. He is also a long-standing member of the Society
of Petroleum Engineers.
BAIDA IQLIMA is a well
intervention engineer at Pertamina Hulu Mahakam, based in Bandung, West
Java, Indonesia. Her studies have been focused on energy with an alternative
focus on technology. Ms. Iqlima holds a degree in petroleum engineering from
the Institut Teknologi Bandung.