bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arun and South Lhoksukon Fields Production Optimisation by Well Cycling
Authors: Pravasta Erido A. , Susanto Edward , Putra Ardian P. 
Published: October 2013

Abstract
Arun and South Lhoksukon (SLS) are gas fields located in Nanggroe Aceh Darussalam, Indonesia. The first production was commenced in 1977 and 1997 respectively. Condensate and water are produced in association with the gas. During initial production, high gas rate dispersed liquids into gas. As fields get mature, gas rate declines and becomes insufficient to lift the liquids accumulation inside the wellbore which causes liquid loading phenomenon.
A well cycling program was implemented at Arun and SLS to overcome the liquid loading phenomenon and optimize mature wells production with minimum cost compared to other deliquifaction methods. The basic principle of well cycling program is to build up the Bottom Hole Pressure (BHP) and drain the liquids back into formation by shutting in the interest wells for a certain period of time. When the well is brought online, liquids accumulation in the wellbore can be lifted as BHP increases. The program is conducted regularly when gas rate drops to optimize the production.
The contribution of well cycling program to Arun and SLS production has been increasing gradually in the past few years. This paper outlines Arun and SLS well cycling operations, monitoring program, cycled well example, and its contribution to overall field production.
Prehydrating High-strength Microspheres in Lightweight Cement Slurry Creates Value for Offshore Malaysian Operator
Authors: Abdullah Mohd Nordin , Bedford David , Wong Suei Ru , Yap Hui San 
Published: October 2013

Abstract
Casing cementation across depleted reservoirs can be challenging because conventionally weighted cement slurries can induce losses and damage the permeability of formations caused by the higher associated hydrostatic pressure they exert on the wellbore. Therefore, when such pressure-related concerns exist, lighter-weight cement slurries are often preferred. For an offshore Malaysia operator, a lightweight cement slurry was proposed to reduce hydrostatic pressure and prevent losses and formation damage. However, instead of a water-extended lightweight cement slurry, a high-performance, lightweight (HPLW) cement slurry consisting of high-strength, hollow microspheres was designed.
Special bulk blending and transportation are normally required for these HPLW slurries because of the large bulk volume and low specific gravity (SG) of high-strength, hollow microspheres. In this case, because of limitations related to the rig’s storage capacity, the microspheres could not be stored conventionally and used as a dry additive to the slurry during mixing. Instead, an alternative solution involving prehydrating the high-strength microspheres with liquid additives and mix water in the mixing pits was implemented. This paper discusses the procedures used during cementing operations and details the value of using this mixing method.
Solving Hard/Abrasive Sedimentary and Igneous Formation Challenge: New PDC Bit Design Reduces 6-in Section Drilling Time By 47%
Authors: Peytchev Peter , Malik Sumit D. , Varghese Roy , Doodraj Sunil , Srinivasan Sudarsan , Benny Praveen , Raghav Sanjeev , Narayanan Shine 
Published: October 2013

Abstract
The 6"hole section in Raageshwari Field NW India (onshore) is typically between 600-800m long and highly challenging in terms of formation strength and abrasiveness. Lithology in the upper part is composed of sandstone, claystone and weathered basalt with unconfined compressive strength (UCS) between 3-5kpsi. The lower section contains basalt, felsic and sub-felsic igneous formations with UCS range of 15-30kpsi.
Historically, a two bit strategy was employed. First, a PDC bit on a positive displacement motor (PDM) bottom hole assembly was used to drill the soft 6" section until ROP dropped to an unacceptable level. The BHA was then pulled and followed by a diamond impregnated bit on a turbine BHA to drill the very hard volcanics. Typical average on-bottom ROP for the entire section was 4.5m/hr and took approximately 170 hours to reach total depth (TD).
To reduce costs, new technology was proposed to improve bit durability in the hard/abrasive volcanics and drill the entire 6" section in one run at a higher ROP. Recent bit and drilling data from offset wells was analyzed to assist in developing a new, cost effective PDC design to replace the expensive diamond-impregnated bits and drill the 6" hole section in one run. The study resulted in a new six-bladed PDC bit with 13mm cutters that incorporates superior cutter technology to improve durability and resist physical and thermal degradation. The design includes a row of backup cutters in the shoulder area to increase radial diamond volume for maximum durability.
The new PDC bits have been run on a motor and rotary steerable bottom hole assemblies and drilled the 6" section on three consecutive wells in Raageshwari field totaling 2328meters with an average ROP of 10.7m/hr. This represents approx. 47% decrease in drilling time compared to that previously achieved by Impreg/TCI bit runs. Typically, the new bits are pulled in re-runable condition. This improved performance has saved the operator approximately six-days of rig time and approximately USD 480,000/well.
An Improved Oil Recovery of Subsequent Water Flooding by Reuse of Residual Polymer in Reservoirs
Authors: Pei X. , Liang Y. , Zhou W. , Wang X. , Li G. 
Published: October 2013

Abstract
Satisfactory production increase and water-cut decrease has been achieved from polymer flooding in Daqing oil field, and the recovery increased by ten percentage points. However, significant residual oil and polymer solution still left behind polymer flooded reservoirs due to the effect of heterogeneity, so how to reuse the residual polymer solution prior to the subsequent water flooding is meaningful, which can both develop the remaining oil effectively and reduce the cost of profile control remarkably. Under simulating the actual field injection rate, this paper for the first time studied the presence form and residual amount of polymer solution in polymer-flooded cores, with permeability variation factors of 0.6-0.7. Then through analysis of residual polymer distribution and subsequent water breakthrough characteristics, cationic polymer particles were injected to react with the residual polymer for profile control, experimental results show the subsequent waterflood recovery increased more than 10 per cent. Field application indicates the injectivity of high-permeability profile modified intervals was limited, the injection profile has been improved effectively, and water cut of the central producers was reduced by 4.45 per cent. Polymer flooding has ended in more and more Chinese oil fields, this technique can be used as an effective means to further improve the oil recovery of subsequent water flooding in these fields.
VSP Surveys Aid Interpretation by Imaging Layers Not Visible in the Surface Seismic: Two Case Histories in Indonesia
Authors: Human Tertius , Muchtar Aldrin , Kunaifi Sunawar , Giyatno Seno 
Published: October 2013

Abstract
Genting Oil Kasuri Pte. Ltd. is operating in the Kasuri field in West Papua, Indonesia which is predominantly a gas field. Surface seismic was acquired over this area, followed by processing and interpretation. The drilling campaign ensued shortly afterwards and during drilling of the initial wells, a number of anomalies were encountered. It appeared that there were more layers present in the subsurface than were initially visible and interpreted from the surface seismic. A strong reflector at the Kais Limestone boundary may have caused reflections from deeper layers to be masked and not clearly visible on the surface seismic.
To get a clearer image and better understanding of the subsurface image, a number of VSPs were conducted. This paper shows two case studies and discusses the VSPs and results obtained in wells which are referred to here as Well-1 and Well-2.
Multistage Fracturing Proves Oil Potential in Low-Permeability Reservoirs in Thailand’s S1 Basin
Authors: Toempromaraj Wararrit , Sethavanish Somporn , Sompopsart Suwin , Vattanapornpirom Kanda , Anaskin Alexey , Wattanasuwankorn Reawat 
Published: October 2013

Abstract
Low-permeability sandstone formations in a deviated well were drilled and completed in 2010 by an oil company in Thailand. Openhole logging data and reservoir simulation modeling of multiple zones showed that the well would not produce because of tight formations. Artificial lifting calculations showed that the well was not likely to achieve hydrocarbon production targets for this well in its current condition. Multistage hydraulic fracturing was then considered for the well, and a plan was adopted to use this method to improve the well’s production while using reservoir simulations to optimize the fracture design. These methods were meshed with the completion and cleanout strategies to improve the well’s performance. The fracturing design was incorporated into a complete operational procedure, along with contingency plans, a decision tree, and an integrated communications plan to allow for any eventuality.
The careful planning resulted in the first successful multistage hydraulic fracturing operation in a deviated well in Thailand. The success resulted from careful planning, fluid testing, and a completion design that was fit-for-purpose, in conjunction with the well testing, to provide an excellent operational stimulation plan and execution.
Better-than-expected production from the well demonstrates that multistage fracturing in a deviated well in north Thailand can be successful and that this is a viable method for enhanced oil recovery (EOR) and improved well economics. This paper presents the well production results and operational procedures used to demonstrate that multistage fracturing is a viable method of completion in Thailand. Pressure matching and leakoff information gained from this operation will be of value in future fracturing operations to help improve those treatment designs
Introducing Integrated Surface & Subsurface Sand Management Systems for Rigless Interventions in East Malaysia
Authors: Zaki Zaini M. , Gornescu Bogdan C. , Saebi Shahryar , Whitney Patricio A. , Veysalli Elshan 
Published: October 2013

Abstract
One of the main challenges in the well intervention in offshore brown fields prone to sand production is both subsurface sand handling and also surface sand handling during the flow back and well cleaning. The field of interest is located offshore in East Malaysia. The field had been producing for almost three decades and is prone to sand production with no capabilities of surface sand handling.
This paper describes the integrated solution to address sand production on both surface and subsurface, targeting sand production from the unconsolidated reservoirs but also from well clean up before and after well intervention. In order to provide a cost effective solution for the new potential layer below the existing gravel pack zone, through tubing gravel pack technique was chosen as the sand control technique. This enabled the new zone to be produced in the optimum draw down without the risk of having sand production at surface. However prior to that, the rathole for the potential new layer had to be cleaned up using coil tubing. The sand and debris from this cleanout had to be circulated out to surface and needed to be separated before being disposed properly onshore. A cyclonic desander was temporarily installed on surface to achieve this. As a result, the integrated system provided overall solutions where downhole sand control was achieved and the cleanout fluid was free from solids to ensure no cascaded damages to the existing process facilities.
The system permitted to execute two wells cleanups, one through tubing gravel pack while complying with the very strict sand content limitations – particle size less than 45 microns and not more than 15pptb. The newly introduced technologies proved to be fit-for-purpose and robust, complying with sand content limitation as well as with all the other constrains.
The General description in term of operations and installation of such system as well as lessons learned and recommendations have been outlined in the paper that can be used as a reference for similar applications in the near future.
3D Sesimic Reprocessing for Geophysical Analysis of Sea Bottom, Seabed Mapping and Geohazard Clarification
Authors: Coral Juan Carlos , Paone Francesco , Marceglia Andrea 
Published: October 2013

Abstract
This paper presents a case study from the ENI operated Muara Bakau PSC (Jangkrik) on the East Kalimantan shelf edge and the west slope of the Makassar straits. The paper discusses the resolution and accuracy of Short-Offset Processed 3D Seismic Data (SOPS) and the applicability of the resulting Digital Terrain Models (DTM) for seabed mapping and initial field development planning.
For this case study a SOPS DTM of 12.5x12.5m grid spacing was generated covering a total area of 330 Km². A somewhat smaller area was later surveyed utilising an Autonomous Underwater Vehicle (AUV). The resulting AUV DTM was of 1x1m grid spacing. A number of exploration wells were already drilled within the area and accurate water depth measurements were performed from three of those wells. This provided the opportunity to evaluate the SOPS DTM accuracy and resolution. The results of the evaluation are presented in this paper. In the Jangkrik Project development, the SOPS DTM execution at early stage (during Concept Selection) allowed to:
Progress the subsea system design of a "fast track" project without waiting for site geophysical survey (AUV) Make key decisions at early stage avoiding the cost and time impact of later changes such as: One well (JK 7) was relocated because initially positioned within a canyon
Sensitive Area Mapping; The Important Step in Establishing the Oil Spill Response Strategy for Offshore Operations
Authors: Adi I. D. , Damar A. 
Published: October 2013

Abstract
Fast, accurate and immediate response is required in case of oil spill occured from the offshore oil and gas activities to minimize the impact to the environment and prevent from the bad reputations. The response strategy should consider the resources availibility and sea condition uncertainity. Every area that may experienced oil spill in the sea should have a map of priority area to be protected. Furthermore this map should be updated in certain period of time incorporated satellite image analysis, field data measurement and validation, as well as Environmental Sensitivity Indices (ESI). ESI was determined based on 3 variables namely vulnerability, ecologies, and socio-economics. The results will be categorized as very sensitive, sensitive, moderate, less sensitive and not sensitive. The study area are in the south eastern coast of Lampung in Sumatra Island until along the north western coast of Java islands, in the area of latitude between 040,24’25.50"S and 06010’45.57"S and meridien between 105045’4.11"E and 107049’81"E South East Sumatera. Since the study area is very huge, it is divided into 3 divisions and each division consisted of 16 units of analysis. The sensitivity area mapping shows that the most sensitive area for division 1 is the locations surrounding Way Kambas National Park, while in the division 2 is the location surrounding Jakarta Bay and all areas in the division 3 which is Kepulauan Seribu. Sea condition uncertainity is represented on oil spill simulation using OSIS (Oil Spill Information Systems) software. The results shows that the most likely impacted area when the oil spill occurs in the sea lane and in the oil companies activities are Kepulauan Seribu in Division 3 with the probability of 83%, Jakarta Bay in Division 2 with the probability of 75%. Meanwhile, the probability of East Lampung Coast in Division 1 is 0%. Application of ESI combined with oil spill dispersion model is a robust method in defining the most effective strategy in combating strategy of oil spill. This method can be applied in determining the priority ranks of action in protecting the shoreline impacted by the oil spill.
Pipeline Integrity Management System in South East Sumatra Offshore
Authors: Habil Mohammad 
Published: October 2013

Abstract
Many current oil fields in the world were developed several decades years ago that have the facilities more that 30 – 40 service years or already over the design live. Consequently this requires some effort to ensure that the integrity of all facilities is still acceptable. These facilities are including pipelines to deliver hydro carbon which may be laid at onshore or offshore. South East Sumatra block is as an offshore operation operates more than 800 KM long covering 136 pipelines, in which more than 50% of them had over the design life. Various diameter of pipelines are installed between 4" – 22" and delivering of trace oil, multi phase fluids, produced water, sea water, wet and dry gas. PIMS was introduced since three years ago in order to identify the integrity of pipelines, the risk, probability of failure, consequent of failure, remaining maximum operating pressure, reasonable and efficient inspection, monitoring to be proceeded, proper maintenance and adequate repair to be executed. Also avoid any pollution on environment, especially at the Thousand Island Under Water Park, Jakarta which is about 50 KM from the South East Sumatra oil and gas fields.
Repeat Dynamic Underbalance Perforating in Oman
Authors: Jumaat Mohd Shafie 
Published: October 2013

Abstract
Dynamic underbalance (DUB) is a technique that has been used for many years by many operators to deliver cleaner perforation tunnels so as to achieve better well productivity or injectivity. Its advantage is shown in the laboratory and by many field jobs. Unlike conventional static underbalance perforating, the DUB perforating technique delivers a sharp pressure drop at the time of perforating, which is critical in breaking down the low-permeability zone around the perforation tunnel, commonly known as the crushed zone.
After several years of DUB application in the industry, the technique evolved into the DUB post-perforating technique in which a gun chamber is instantaneously opened at the existing perforations to create a sharp pressure drop to clean the crushed zone. This technique has been successfully applied in both the laboratory and in the field.
Other laboratory work has provided greater insight into the nature of perforating tunnel damage and how effective the standard DUB or post-perforating DUB technique can be in cleaning them. From this understanding and implementation of both DUB techniques, the repeat-DUB technique is proposed.
The repeat-DUB technique delivers perforations by the standard DUB technique and subsequently treats them with the DUB post-perforating technique, all in the same job. Although the DUB techniques produce perforations with a good productivity index (PI), the repeat DUB sequence further enhances the PI. This paper discusses the concepts and why and where this technique enhances the PI, including a review of, the basics of the DUB technique in comparison with various surging techniques. The repeat-DUB technique has been applied to 35 wells in a field in Oman with good results.
Aceh Operations Mature Field Management: Arun Assets Consolidation and North Sumatera Offshore (NSO) Liquid Handling
Authors: Avida Hanifatu , Soedarmo Auzan A , Utama Dheli P 
Published: October 2013

Abstract
This paper describes integrated asset management team efforts to sustain safe and profitable production of mature fields. Two case studies are presented: Excess assets consolidation at the onshore Arun field in Aceh province, and reservoir liquid breakthrough handling at the North Sumatera Offshore (NSO) field.
The Arun field has been producing since 1977. Currently more than 99% of expected ultimate gas recovery has been produced. Surface facilities were designed for a peak capacity of 3,500 MMSCFD with multiple well clusters and production trains. With production declining to less than 5% of design capacity, the majority of facilities have significant excess capacity. Asset consolidation efforts were started in 2004 with the Arun Cluster Consolidation Project (ACCP) to centralize gas dehydration and booster compression facilities into one cluster. In total, ACCP reduced active assets by 60%, operating expense by $350K annually, and fuel gas consumption by 9 MMSCFD. The ACCP was followed by the Liquid Handling Project (LHP) to consolidate liquid separation and transfer facilities from four clusters into two. Completed in 2010, the LHP reduced manpower by ~ 600 man-hours per year and avoided machinery reliability issues due to operation below turndown limit.
Liquid handling is often a major bottleneck for offshore gas facilities, especially after formation water breakthrough on platforms that treat and discharge produced water overboard. Weight and footprint limitations restrict flexibility for de- bottlenecking. The NSO platform was designed with a total liquid handling capacity of 2,500 BPD, subject to a regulatory overboard water quality limit of 50 ppm oil in water content. Improvements in the chemical treatment and physical separation processes were utilized to increase capacity by 40 percent to 3,500 BPD while continuing to meet condensate quality and overboard water targets, enabling production to be maximized in spite of increasing water breakthrough.
Assessment of the Effect of Casein Phosphopeptide–amorphous Calcium Phosphate on Postoperative Sensitivity Associated With In-office Vital Tooth Whitening
Authors: Maghaireh GA , Alzraikat H , Guidoum A 
Published: October 2013

SUMMARYThe aim of this study was to evaluate the efficacy of tooth mousse containing 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) in reducing tooth sensitivity associated with in-office vital tooth whitening. In-office tooth whitening was performed for 51 participants using 35% hydrogen peroxide gel in a single visit. After the procedure, each participant was randomly assigned to one of three groups: gel without desensitizing agent (n=17), gel with 2% sodium fluoride (n=17), gel with 10% CPP-ACP (n=17). A small amount of the desensitizing gel assigned for each participant was applied directly on the labial surfaces of teeth and left undisturbed for three minutes. The participants were asked to apply the gel assigned to them for three minutes twice daily after brushing their teeth, and to continue this for 14 days. The participants were asked to return for follow-up visits after 24 hours and on days 3, 7, and 14, at which time teeth shade changes were assessed by one evaluator using a value-oriented Vita classic shade guide. The incidence, duration, and intensity of tooth sensitivity experienced was self-assessed on a daily basis for the 14-day study period using a visual analog scale (VAS). The effect of the three gels on tooth sensitivity was assessed using one-way analysis of variance and a χ2 test (α=0.05). The general linear model was used to compare intensity-level differences in the three studied groups and for shade stability over the follow-up period. The results of this study showed that all three gels decreased the intensity of sensitivity associated with tooth whitening. The intensity of sensitivity was lower in the fluoride group than in the other two groups; however, it was not statistically significant (p=0.112 and p=0.532 on day 1 and day 2, respectively). The average shade change was 6.8. None of the tested materials affected the efficacy of tooth whitening, but the shade change among the fluoride group showed more color stability than that of the other two groups. This study suggested that using a gel after tooth whitening can reduce the intensity of tooth sensitivity associated with in-office whitening procedures without affecting the efficiency of tooth whitening. However, it failed to demonstrate that using a 10% CPP-ACP could provide additional therapeutic benefits.