bluuebunny/crossref_metadata_2025_split huggingface dataset:
Agitation Tools Enables Significant Reduction in Mechanical Specific Energy
Authors: Azike-Akubue Vivien , Barton Steve , Gee Ryan , Burnett Timm 
Published: October 2012

Abstract
Mechanical Specific Energy (MSE) is a term used by the oilfield drilling industry to describe several formulae quantifying the energy input within a drilling system. MSE mainly describes the Mechanical (WOB and Torque), for a given unit (Length, area or mass), and the energy required to do the work (i.e. force, time, distance).
Although several different formulae have been developed in an attempt to quantify this value, the accepted industry standard is as below:
E s = W A X + 120 π N T A X R
Where:
Es = Specific Energy (psi) N = Rotary Speed (rpm)
W = Weight on Bit (Ibf) T = Drilling Torque (ft-lbf)
Ax = Borehole x-sectional area (inA2) R = Rate of Penetration (ft/hr)
When using surface parameters such as RPM and Weight, the drill string and BHA frictional losses are the primary source of energy loss in typical drilling systems. As such, introduction of solutions to reducing these frictional losses would have a significant impact on reducing the MSE of the system. This would lead to improved drilling efficiency, thus lower drilling time and reduced costs.
The effect of having an axial oscillation tool (AOT) in the drill string has been previously demonstrated to be effective, particularly in applications where sliding with steerable motors has been problematic. Axial oscillation in the drill string is generated through a series of pressure pulses coming from one part of the AOT. The pressure pulses act on the pump open area of a shock tool, generating the axial motion required to reduce friction, improve the weight transfer to the bit, reduce reactive (and thus overall) downhole torque. The hydraulic vibration also enhances the performance through reducing friction.
The AOT's influence on reducing friction in a constant axial oscillation helps reduce the total friction significantly. Friction reduction enables the entire suite of drilling parameters to be optimized through proper weight transfer, which in return, reduces the chance of buckling, reduced torque, increases ROP, and increase bit life; all are a source of energy improvement.
Electromagnetic Measurements While Drilling: a Telemetry Solution for Casing-While-Drilling.
Authors: Musa M Zarir , Bt Abdul Aziz Dian Semesta , Budi Setiawan Trigunadi , Hermawan Heru , Kardani Ilen , Askar Ali Mohd Azlan , Sidek Rosli 
Published: October 2012

Abstract
Casing-while-drilling (CWD) operations have become a well-known technology used to minimise drilling time and reduce AFE budget. PETRONAS has drilled several wells in Malaysia by using this technology, and it has proven to be a cost efficient strategy particularly in batch drilling process.
Past CWD operational experiences have demonstrated stark differences when compared to conventional drilling in terms of wellbore surveying and formation evaluation. Weak and noisy signals from mud pulse telemetry were primary issues that required a significant amount of rig time when acquiring measurement-while-drilling (MWD) and logging-while-drilling (LWD) data.
In fact, several significant challenges were encountered. First, the mud pulse signal which traverses from downhole (MWD) to the surface somehow dampened out. Although various types of mud pulse telemetry have been used, significant problems remain. In addition, the signal transmission worsened when seawater was used as the drilling fluid, resulting in nonproductive time due to provisioning ofchange out tools with different configurations for mitigation and trial-and-error purposes. Finally, overall drilling efficiency was reduced as a result of poor signal detection and capturing.
EM-MWD used in combination with gyro-while-drilling (GWD) was identified for implementation when drilling four wells using Tesco CWD technology in the Erb West field. The mud pulse and electromagnetic telemetry systems were executed asa pair to compare captured signal strengths in the same environment, i.e., directional CWD with seawater drilling fluid.
After drilling ceased, the generated results proved that EM-MWD is a viable technology that can be used to overcome signal attenuation issues in a CWD operation. It also minimise health, safety, and environment (HSE) risks as well as established a working model of EM-MWD-CWD. Most importantly, such application reduced rig time by 3.9 days which contributed to 26% of cost saving for the surface section drilling by having trouble free MWD signal detection and faster drilling operation.
Slugs-fracs reassessed well fracturing conditions for Kamennoe field in Western Siberia
Authors: Platunov Andrey , Nikolaev Maxim , Leskin Fedor , kaluder Zdenko , Davidenko Igor , Ganin Oleg 
Published: October 2012

Abstract
Slugs-fracs is one of new-to-field approaches which changed the conditions of wells for fracturing increasing the number of candidates in Kamennoe field Western Siberia. Placing fracturing jobs by slugs of proppant pumped in linear gel successfully implemented in stimulating pay zones in near water intervals with small stress contrast between zones and barriers. A few technical specifics had been used to contribute the success of this methodology such as earlier pumping with near matrix rate to allow more fluid filtration ahead of the main proppant stages before fracture is fully formed. Proppant setting according to Stokes law and dune effects theory were evaluated and considered for design strategy. The slugs-fracs allowed pumping regardless of the wellbore deviation and height of perforated intervals. Post-fracturing results from 120 wells were used for analysis. Significant decrease in initial water cut and sustainable oil production were reported. First slugs-fracs were introduced in the beginning of 2010 and in following 2 years more than 200 hundreds jobs have been pumped across the field. This allowed to drill spots of the field that were previously suspended as result of ineffective fracturing treatments mostly due to high risk of fracture breaking down the water zones.
A Novel Effective Triglyceride Microemulsion for Chemical Flooding
Authors: Jeirani Z. , Jan B. Mohamed , Ali B. Si , Noor I. Mohd , See C. H. , Saphanuchart W. 
Published: October 2012

Abstract
This paper presents determination of aqueous phase composition of a new triglyceride microemulsion in which the triglycerides constitute the whole oil-phase of the microemulsion. Palm oil was used as the oil phase of the microemulsion. Experimental results indicate that the optimum triglyceride microemulsion was achieved when equal mass of palm oil and the aqueous phase containing 3wt% sodium chloride, 1wt% alkyl polyglycosides, 3wt% glyceryl monooleate, and 93wt% deionized water were mixed. The formulated composition of the aqueous phase was able to form translucent Winsor Type I microemulsion with palm oil at ambient c nditions. The measured interfacial tension between the optimum microemulsion and the model oil, which is n-octane in this study, was 0.0002mN/m. The maximum tertiary oil recovery of 71.8% was achieved after the injection of the optimum microemulsion formulation to a sand pack. The significant increase in total oil recovery (87%) suggests the effectiveness of the triglyceride microemulsion formulation for enhanced oil recovery. Its capability in recovering additional oil (4.3% of the trapped oil after water flooding) compared to a typical polymer in tertiary oil recovery indicates the efficiency of the optimum triglyceride microemulsion formulation.
A Great Way to Make your Invert Emulsion Fluids Green!
Authors: Wagle Vikrant , Kulkarni Dhanashree , Maghrabi Shadaab 
Published: October 2012

Abstract
Invert emulsion fluids (IEF) typically consist of an aqueous brine internal phase emulsified into an oil external phase. Conventionally, an aqueous solution of calcium chloride is used as the internal phase to balance osmotic pressures while drilling through shales. The use of traditional chloride salts, however, can cause disposal issues and environmental concerns while drilling onshore wells. To address these concerns and to provide an eco-friendly green invert emulsion fluid with improved technical performance, two types of salt-free IEFs have been developed: clay-based and clay-free.
The salt-free IEFs comprise a biodegradable and non-toxic internal phase to mitigate the potential negative effects of a brine-based IEF. The internal phase of the new fluid achieves 70% biodegradation in 28 days in accordance with OECD (Organisation for Economic Co-operation and Development) method.
The 12.0-ppg and 16.0-ppg salt-free IEFs, both clay-based and clay-free, were stable at temperatures greater than 300°F. The salt-free clay free IEFs were formulated in the presence of a novel organic secondary emulsifier. These salt-free fluids exhibited comparable rheological and fluid loss properties and offered improved shale inhibition as compared to conventional IEFs. The salt-free IEFs showed good tolerance to contaminants and static ageing. Shale erosion and shale swelling performance of the 12.0-ppg and 16.0-ppg salt-free IEFs were comparable with the CaCl2 based conventional IEFs. This paper presents experimental data corroborating the technical and environment performance of salt-free IEFs.
Salt-free drilling fluids formulated with this biodegradable and non-toxic calcium chloride alternative provide a solution to environmental concerns. The novel salt-free clay free fluids also eliminate the use of organophilic clay, thereby resulting in an IEF with low solids content, better equivalent circulating density (ECD) control and faster rates of penetration (ROP).
Addressing the Challenges of Production Forecasting in the Remote Highlands of Papua New Guinea
Authors: Sullivan S. , Rowse J. 
Published: October 2012

Abstract
Operational conditions in the remote highlands of Papua New Guinea bring a multitude of challenges including complex geology, steep jungle terrain, extreme rainfall, a sensitive ecosystem, a variety of landowner cultures, ageing facilities, mature reservoirs, and fraught logistics. These factors conspire to increase the complexity of production forecasting well beyond just reservoir performance.
After missing production targets for a number of years, a significant improvement in forecasting was needed to fully capture the uncertainties, both identified and unforeseen. A probabilistic forecasting tool using Monte Carlo simulation has been developed which incorporates assessments of all major variables and takes account of historical performance and system changes.
Successful implementation has resulted in the generation of realistic targets which have been met within four per cent for three years. Further, a clearer understanding of potential threats and opportunities combined with their impact on production has been achieved. These results have delivered material benefits to business planning, decision making and company reputation. Data to be presented on the forecasting tool will describe the quantification of uncertainty for each major variable including reservoir and facility performance, incremental production opportunities, project schedules and major unplanned downtime.
This approach could be applicable to E&P companies operating in difficult conditions worldwide, where unreliable production targets have a major business impact. It is flexible enough for both short and long term forecasts, tracking and reporting, and adaptation to new or changed operating conditions.
Various Methods to Detemine Relative Permeability in Fractured Reservoirs
Authors: khosravi Vahid 
Published: October 2012

Abstract
The relative permeability curves do not share the same degree of acceptance and credibility. This is particularly serious because the estimation of reserves in natural processes and in EOR projects using immiscible fluids (water, gas, steam) heavily depends on relative permeabilities.
Most of the relative permeability in fractured reservoirs measurements are performed through the unsteady state method, by which the reported end points correspond to steady state flow conditions (homogeneous saturation and single phase flow), while the intermediate values are calculated during a transient stage in which sample saturation is not homogeneous. Because of this, the end point saturations should have greater validity than the remaining points in the curve, since the shape of the curves in heterogeneous systems depends - among other things - on the mobility ratio, while it is generally accepted that the end points - if properly extrapolated at the end of the test - are independent from it. It is generally believed that residual oil saturation, Sor, is obtained only after injecting "infinite" poral volumes of water.
In many cases, the production curve, the residual oil saturation and the permeability to water - at such saturation - notably depend on the flow rate used during displacement. Although laboratories take different steps to correct, or not, the measurements performed, they mostly fail to inform what flow rates were used in the lab or the range of application of the reported data. The relative permeability curves presented by the labs are usually continuous along the entire saturation range between Siw and Sor.
Based on the above considerations, it would seem reasonable to conclude that, in order to properly characterize the reservoir, the different displacement mechanisms and flow directions should be studied to analyze their effect on the production curves used to determine the system relative permeabilities.
Introduction of a Dual ESP with Bypass Tubing and Backup Gas Lift System in an Offshore Brownfield
Authors: Zaini Muhamad Zaki , Rivero Maria Elba , Sepulveda Willem , Salim Muzahidin M , Bela Sunanda Magna 
Published: October 2012

Abstract
This paper will outline and discuss the processes involved from planning to conceptual design, detailed design, equipment preparation and onsite execution that has contributed to the successful offshore installation of Malaysia's first dual ESP system. It will also highlight the challenges and issues encountered throughout the project. The well was originally completed in 1989 as a single producer with gas lift. It is closed in 2004 due to high solid production. A workover operation was carried out in end of May 2011 to revive the well. The current producing zone was plugged and abandoned and the shallower producing interval is opened up and completed. Instead of continuing with the status-quo, gas lift strategy the well is completed with a Dual ESP system with bypass tubing, making it the first ever dual ESP installation in Malaysia.
Gas lift has been predominantly used as the main artificial lift strategy in the region. It's relatively ‘cheap’ resources and simple application has been the main driver for oil operator to continue using it as their preferred option. However as the water cut increases and lift gas supply become limited there is a need to have a look on the so called ‘commodity’ artificial lift application. ESP has been seen as one of the most attractive alternatives. The field's first conventional ESP installation with a backup gas lift system in 3 wells was installed in late 2008. In 2010 another ESP with pod configuration was installed. Ever since then, Bokor Project Management team has started to explore on the advancement of ESP system in order to find the optimized design for Bokor Field. However there are several challenges to be addressed. Justification to use a dual ESP system rather than a conventional gas lift system or single ESP configurations that has been done previously in 4 other wells, especially in term of initial cost.The complex installation of a dual ESP system complete with bypass tubing and gas lift backup system which is not a common practice in the areaDesign considerations and challenges for a successful installation. A complete design of a dual ESP for well specific application.Installation challenges of Dual ESP system with bypass tubing and backup gas lift system utilizing a hydraulic workover unit which has limited handling capacity compared to a conventional rig.Surface requirement and limitations of the existing facility for ESP commissioning and startup.
Among others, the paper will discuss on the justification and technical solutions that have been proposed for the installation of the dual ESP system in Bokor field. Lesson learned from the project is also compiled in this paper for any future similar installation in the field
Acidizing Technology in Complex Volcanic Gas Reservoirs--Case Study
Authors: He Liu , Changyu Liu , Honglan Zou , Yang Gao 
Published: October 2012

Abstract
Nowadays, as the deep gas reservoirs in Daqing are explored, the complex volcanic reservoirs have been the major reservoirs in deep natural gas exploration and production. The reserves of volcanic gas reservoirs take up 88% of the total gas reserves. However, the deep complex gas reservoirs may cause heavy pollution during the drilling completion, and some of the barriers between target zones of the wells are very thin, leading to a poor stability. Additionally, because of the complex water/gas relations in the formation, such as appearance of bottom water and water and gas sharing the same formation in some wells, the fracturing operations will induce water channeling. All these facts may cause the failure of the fracturing operations.
Especially, when the fractured formation is close to the water/gas interface, the fractures will easily extend into the water layer. The existence of water in the gas wells directly leads to the reduction of production and recovery rate of the gas reservoirs, or even kills the gas reservoir in the worst cases. For these types of gas wells, acidization technology is a promising solution. It not only avoids the pollution near the wells of volcanic formation, but also chemically dissolves the fillings in the fractures and pores, improves formation seepage flow environment, increases fluid mobility, and finally optimizes the productivity. Acidization technology also has the advantages of low investment and quick payback.
This paper reports the volcanic reservoir acidization technology we developed. The lab test results show that this technology solves the problems of high erosion rate of the oil strings under high temperatures (125-160 degree of Celsius). The acidization technology is applied in three wells, and the productivity of those increases profoundly.
Production of Methane and Water from Coal Seams and the Associated Ground Surface Subsidence- a Numerical Model
Authors: Freij-Ayoub Reem 
Published: October 2012

Abstract
Production of methane from coal seems is achieved by pumping out large quantities of water leading to cleat pressure drawdown and hence methane desorption from the matrix, its diffusion through the micropores to the cleat system and out of the wellbore.
A coupled numerical model is developed within FLAC3D to simulate the production of methane and water from coal seams through depressurization and to investigate possibilities of land subsidence around the wellbore. The axisymmetric model simulates the drilling of a vertical wellbore through a formation containing 2 coal seams. The model couples Geomechanics and fluid flow. Langmuir desorption isotherms control the maximum volume of gas desorbed in the coal matrix at any specific pressure. The cleats are assumed to be initially full of water. Desorption of methane from the coal matrix and its diffusion into the cleat system is assumed to be instantaneous. The geomechanical behaviour of the formations follows a Mohr Coulomb yield criterion.
The model qualitatively predicts the quantities of produced methane and water from coal seams separated, overlain or underlain by lithologies of contrasting permeabilities. The presence of an aquitard between both seams ensures higher methane production and less water production. The highest methane production and least amounts of produced water were predicted for seams separated, overlain and underlain by aquitards. The model can predict the amount of ground surface subsidence in the region around the wellbore. Sunsidence up to 11 cm was predicted near the wellbore.
Thru-Tubing Isolation and Perforating in Large Casing Diameter
Authors: Syafruddin Muhammad , Fauzi Dedi , Ferdian Andru 
Published: October 2012

Abstract
Well-11 produced gas from the Kujung-2 and Kujung-3 (K-2 and K-3) carbonate formation of Ujung Pangkah Field. Even though it was producing from the biggest reservoir zone, the well had to be shut in due to watering out in two years. High molecular weight polymer was injected to shut off the water zone but with no success. The work over job aimed to isolate the watered out zone (K-2 and K-3) and to access K-1 formation which had never been produced. This rigless operation was carried out on an-manned production platform.
Thru-tubing isolation inside the 9-5/8-in. casing was the biggest operational hurdle of the project. The challenges addressed were; high expansion ratio of the inflatable plug; uncertainty of the casing's condition due to the sour gas environment; and a cement bailer operation to permanently isolate the formation. Perforating was successfully executed in the selected zone using deep-penetrating shaped charges. The results were satisfactory and the well produced three times more gas than expected.
This paper presents the strategies, challenges and the lessons learned for zonal isolation using a thru-tubing inflatable bridge plug combined with cement and the perforating of the K-1 formations to optimize the gas recovery factor.
Taking the Third Generation Multiphase Meter Subsea - Challenges and Design Choices
Authors: Berge Finn Erik , Tyssen Ingar 
Published: October 2012

Abstract
This paper presents an overview of the processes, design and technology choices behind taking the latest multiphase meter (with new measurement, visualization and tomographic techniques) subsea.
The paper will look at applications for the new meter and the benefits of designing a subsea version. With Asian operators' increased focus on EOR and flow assurance, harsher offshore environments and production over a wider range of process conditions, the new meter will have significant applications for accurately measuring flow rates under varied conditions.
The paper will describe the development process behind the new subsea meter. It will examine how a new flow computer was developed to enhance communications, the extended GVF range, and improved salinity measurements to allow more accurate measurements of flow in high water liquid ratio (WLR) and when GVF is high.
The paper will look at the design challenges in adapting what was previously a topside meter for HP/HT environments subsea and the challenges of developing a more compact version without technology compromises. This compactness is crucial, with many subsea manifolds in Asian fields already crowded with instrumentation.
The paper will provide an important technical contribution towards the goal of increasing flow assurance in Asia's offshore fields and will demonstrate how the new design concept and technology will be crucial for more complex condition monitoring and intelligent metering in the future.