Samvelova, Marina (Halliburton) | Priatna, Oktaf (Halliburton) | Kristanto, Tutus (Halliburton) | Thian, Kelvin (Halliburton) | Rosland, Eadie Azahar B (Petronas Carigali Sdn. Bhd) | Sandanasamy, Ronfernandez (Petronas Carigali Sdn. Bhd) | Tashkenbaev, Timur (Petronas Carigali Sdn. Bhd) | Kwang Hui, Nicholas Foo (Petronas Carigali Sdn. Bhd) | Rechoum, Hassan (Weatherford) | Fraser, Mark (Weatherford)
The Sumandak field is located offshore Sabah, northwest of Labuan Island, in Malaysia. The majority of the reservoirs in this field are oil producers subject to sand production at some point during well life.
The subject well was completed using a typical completion design for the current field, running standalone screens inside an 8.5-in. open hole using 3.5-in. dual and monobore production tubing strings. Several wells in the study field are shut in and not producing because of the significant amount of sand and fines produced to surface facilities and filling the tubing, thus negatively affecting production. To reactivate the wells, remedial sand control techniques were necessary to restore productivity of the reservoir.
This paper presents a through-tubing recompletion method combining mechanical techniques, such as a through-tubing intervention approach, along with downhole equipment and a chemical approach that used a fines control treatment, which helped bond the formation fines in place to assist with restoring initial cementation of the reservoir and reduced the risk of blocking the screen media.
The success of this operation was aided by an intensive laboratory study of cores from the field to optimize the design of the tool assembly and treatment formulation based on the particle size distribution (PSD) profile and production histories from the described wells.
Through-tubing downhole tools were chosen considering tubing and casing sizes, the wellbore minimum restriction, type and locations of the landing nipples, reservoir properties, bottomhole pressures, packer setting depth, length of the reservoir to be recompleted, location of the interval in relation to production tubing, length of the rat hole below the interval, and consideration to repair an existing but possibly damaged standalone screen. An advanced wellbore-cleanout technique for low bottomhole pressure reservoirs that uses an upper jet and washdown jet nozzles in conjunction with coiled tubing (CT) was performed before the consolidation treatment.
This is the first time a through tubing recompletion of the existing wellbores has been implemented in the Sumandak field in offshore Malaysia. This methodology has integrated new and existing technologies to achieve successful sand control operations to bring a well back on production after having been shut in because of sand production. It helped reactivate the wells and improve the recovery reserve rate of the field.
After this successful treatment, productivity of the well has exceeded expectations compared to conventional gravel packed wells. Such placement techniques created many opportunities to effectively and economically treat and revive wells experiencing similar production issues.
Rohani, M. J. (Petronas Carigali Sdn. Bhd) | Sha'ari, F. A. (Petronas Carigali Sdn. Bhd) | Rahman, A. A. (Petronas Carigali Sdn. Bhd) | Ismail, W. M. Wan (Petronas Carigali Sdn. Bhd) | Chan, N. (Fugro Singapore Pte. Ltd.) | Tho, K. K. (Fugro Singapore Pte. Ltd.)
A review of the performance of jack-up rig spudcan penetration predictions in Malaysian Waters over the past ten years is performed with the aim of improving the predictions for future deployments. This work is part of an ongoing initiative to further improve the safety and efficiency of jack-up rig deployments in Malaysian Waters.
During the first phase of the study, field measured spudcan penetrations at maximum preload from 100 jack-up rig emplacements in different subsoil conditions are compared against the corresponding spudcan penetration predictions. These spudcan penetration predictions, which originated from third parties and are presented anonymously, consist entirely of Class-A predictions made prior to the jack-up emplacement. A significant scatter is noted between predicted and actual spudcan penetrations. Possible causes of discrepancy between predicted and actual spudcan penetration depths in Malaysian Waters are postulated.
In a significant proportion of the cases reviewed, the final spudcan penetration is found to be governed by bearing capacity in clay. Consequently, bearing capacity solutions for clays detailed in
The next phase of the study also aims to evaluate the need for revised calibration factors to
Rohani, M. J. (Petronas Carigali Sdn. Bhd) | Sha'ari, F. A. (Petronas Carigali Sdn. Bhd) | Rahman, A. A. (Petronas Carigali Sdn. Bhd) | Wan Ismail, W. M. (Petronas Carigali Sdn. Bhd) | Chan, N. (Fugro Singapore Pte. Ltd.) | Tho, K. K. (Fugro Singapore Pte. Ltd.)
Sand overlying clay soil profile is typically associated with punch-through risk during preloading. Computation of load-penetration response is usually performed in accordance with methods detailed in
The LDFE analysis is performed using the Coupled Eulerian-Lagrangian functionality in ABAQUS. In an Eulerian analysis, the spatial position of the nodes is fixed and materials are allowed to flow from one element to another element. Owing to the large deformation characteristic of the spudcan penetration problem, the Eulerian approach is an attractive solution strategy. In order to simulate the phenomena of progressive strength degradation with increasing accumulation of plastic deformation in the clay layers, a modified Tresca material model with strain-softening is implemented via a user-defined subroutine. The installation of the spudcan is modelled as a continuous spudcan penetration problem ("pushed-in-place") with the spudcan initially positioned at the mudline and progressively pushed downward to the final penetration.
When compared against the spudcan penetration curves based on conventional methods, the numerically simulated load-penetration response is different in three important aspects. Firstly, the LDFE model indicates that rapid leg penetration will occur over a distance of approximately 8m as compared to 20m computed based on conventional methods. Secondly, the LDFE model shows a modest 10% reduction in bearing capacity over the depths at which rapid leg penetration is expected to occur while calculations based on conventional methods indicates a 45% reduction. Lastly, the LDFE model predicted a final penetration depth that is significantly shallower than that computed using conventional methods.
With a LDFE model, it is not necessary to prescribe the failure mechanisms a-priori. The governing failure mechanism, which is a manifestation of the natural tendency for failure planes to develop along the weakest admissible path, is an output from the simulation. In contrast, a conventional spudcan penetration analysis is performed based on a "wished-in-place" approach without taking into account of the occurrence and effect of the composite footing formed by the spudcan and the sand plug. In the conventional approach, the sand layer is assumed to diminish as the spudcan penetrates beyond the clay-sand interface.
Norintan Farina, Haziq (Dimension Bid (Malaysia) Sdn.Bhd) | Hafiz, Azzad (Dimension Bid (Malaysia) Sdn.Bhd) | Safwan, Aliff (Dimension Bid (Malaysia) Sdn.Bhd) | Norfasya, Norfasya (Dimension Bid (Malaysia) Sdn.Bhd) | Xiong, Choi Yee (Petronas Carigali Sdn. Bhd) | Zawawi, Ahmad (Petronas Carigali Sdn. Bhd) | Yusmanizeil, M. (Petronas Carigali Sdn. Bhd) | Aisyah, Siti (Petronas Carigali Sdn. Bhd) | Idham, M. (Petronas Carigali Sdn. Bhd) | Wahyudeen, M. (Petronas Carigali Sdn. Bhd)
Caliper survey is well known for its accurate measurement of inner casing and tubing since the introduction to the market few years ago. From the survey, most pipe integrity issues with failure size as small as pitting can be measured to a better understanding on the tubing conditions. Most of the failures on pipe developed over time and small pitting more than often turn into damaging large hole as time goes by. Thus, caliper survey provides an ideal solution for monitoring the pipe integrity condition.
Not until the recent innovation of a new electromagnetic tool altered the perspective on monitoring the pipe integrity condition. By combining with caliper tool, it improves the pipe integrity survey by identifying the location of weaknesses; in specific the exact point of metal loss, as well as to measure the thickness of the tubing. Applying the remote eddy current concept, the magnetic wave will travel from the wave generator, along the outside of the casing before passing back through the 12 sensors mounted on the inside of the tool's bowsprings. The casing thickness affects the arrival time, phase and amplitude of the returning signal and this info will be analyzed with the improved 3D visualization software and statistical software.
Three (3) wells; A, B and C were completed during 1990's. The wells have high CO2 content at 9–15%. Surface facilities in the field have limitation in handling high CO2 fluid, thus these wells were producing intermittently from 1996–2010. An upgrading of surface facilities were undertook from year 2012–2014 to maximize the technical potential of the wells in the field. Workover job was agreed upon the upgrading but intervention team has another idea in looking into the matters. A logging survey was proposed consists of caliper, electromagnetic and pressure gauge to evaluate the conditions of the tubing integrity. The logging involved the entire tool associated in real time and tandem, the first time ever done in this region. The results from the survey showed differences of corrosion percentage between caliper data only and combination of caliper and electromagnetic tool. Combining these techniques of survey in tandem gives a more details corrosions percentage and thickness compared to caliper only. It also minimized the operation logging time and well downtime. In conclusion, it was found that the current tubing thicknesses of these wells are within the allowable corrosions rate, consequently workover campaign was dropped and roughly around USD 30 Million had been saved.
The comprehensive strategy on running these surveys in tandem provided in this paper can be used as guidance for an innovative approach in corrosion monitoring.
Horng, Chen Jiun (Petronas Carigali Sdn. Bhd) | Nordin, Norbashinatun Salmi (Petronas Carigali Sdn. Bhd) | Nuriyadi, M. Azrul (Petronas Carigali Sdn. Bhd) | Samsudin, Noren (Petronas Carigali Sdn. Bhd) | Kasim, Abdullah (Petronas Carigali Sdn. Bhd) | Hoe, Chum Wai (Schlumberger) | Rahman, Roziman Abdul (Schlumberger)
Moving into electronic age, completion tool and accessories are getting advanced. For the past 10 years, permanent downhole gauge (PDG) technology has been supported with tremendous investment in its research and development. This pacing technology is no longer new to the industry oil and gas operators. Some operators have made it as standard practice but however, some operators are still performing financial model analysis to justify for PDG installation. Is it a real need to install PDG or it is just another fancy luxury that give limited financial returns to the project? How much data is required by petroleum and reservoir engineer to understand the reservoir? This paper presents in detailed about the financial model analysis and demonstrates the tangible and intangible benefit of the PDG and the added value to full field life cycle.
Ghazali Abd. Karim, M. (Petronas Carigali Sdn. Bhd) | Hj Salim, Mat Ali (Petronas Carigali Sdn. Bhd) | Md. Zain, Zahidah (PETRONAS Research & Scientific Services Sdn. Bhd) | Talib, Noor Nazri (PETRONAS Research & Scientific Services Sdn. Bhd)
Bokor field was selected as the first field in Malaysia for Microbial Enhanced Oil Recovery (MEOR) technology application which utilizes micro-organisms to facilitate, increase or extend oil production from reservoir through the production of biochemical such as biosurfactant, solvents, gases and weak acids. The field was selected due to its high viscosity crude (4 to 10 cp) and low oil specific gravity of 20° API which could resulted in low recovery factor in major reservoirs ranges from 19% to 25% of its original oil in place. This technology also seems to be attractive for the field as it was initially thought to be potential for for reducing the viscosity of the oil and thus improve oil recovery. In addition, reservoir properties for major reservoirs in Bokor field conform to the basic screening criteria of the MEOR application.
This paper mainly discusses the results of the pilot project on MEOR technology application in Bokor field1. A feasibility study focusing on candidate selection and comprehensive laboratory analysis was conducted to investigate the feasibility of this technology for improving oil production/recovery. Generally, the feasibility study had indicated that there is a potential oil production improvement with no near wellbore impairment. Biodegradation study on the crude sample indicates complete removal of normal/branched alkanes and partial removal of aromatics due to in-reservoir alteration. Laboratory inoculation on the wellhead crude sample indicated that the microbes were able to slightly reduce the viscosity, break the emulsion and increase the solubility of high molecular weight component without damaging the reservoir. In order to prove the laboratory results and further assess the impact to oil production, a pilot test on three (3) selected wells were carried out. A comprehensive monitoring strategy was developed and the performances were monitored for 5 - 6 months.
Over 5 months period, results from the pilot were found to be encouraging. Significant increase in oil production rate and reduction of water cut were observed demonstrating the effectiveness of MEOR application. The average oil production rate for the period increases by 270 b/d which is equivalent to 47% oil incremental.
Overview of MEOR Technology
Microbial Enhanced Oil Recovery (MEOR) is a technology using micro-organisms to facilitate, increase or extend oil production from reservoir. The concept is more than 40 years old, however, early proposals were poorly conceived and in most cases had no practical value. Recent studies have developed microbial biotechnology to resolve specific production problems in reservoir. MEOR processes involve the use of in-reservoir micro-organisms or specially selected natural bacteria which are capable of metabolising hydrocarbons to produce organic solvents, like alcohols and aldehydes, fatty acids surfactants and other biochemical that are known to be effective at encouraging oil mobility.