bluuebunny/crossref_metadata_2025_split huggingface dataset:
Achieving Brazilian Extended Reach Drilling Records on Polvo Project with Ultra High Torque Connection
Authors: Biddle Nathan , Osorio Luciana , Arevalo Hector , Velho Marcelo , Flores Vincent , Granger Scott 
Published: May 2016

Abstract
The Polvo project is a platform based drilling rig located ~95km off the Brazilian coast in the Campos Basin. The field consists of two distinct reservoirs, a carbonate reservoir to the southwest, and a sandstone reservoir to the east. The Polvo project began drilling in March 2007 and has since drilled a total of 32 wellbores. The wells range in difficulty from "shortreach" to "very extended reach" wellbores. The deviation is from 3–7º DLS at angles of 30–92º. Wellbores are 3-dimensionally designed in order to improve total reservoir exposure.
Extended reach, deep and high deviation wells require the use of a drill string that has both higher torsional yield strength drill pipe body and greater torque capacity tool joints than are afforded by standard API connections. VAM Express double shoulder connection has been designed in order to address the drilling challenges linked to the development of such complex wells. This proprietary high torque connection incorporates four major design features allowing pushing further the drilling envelope limits: quick rig make-up, high torque performance, user friendly and durability.
After beginning the project and platform placement, it was discovered that sandstone reservoir targets further to the east had higher productivity than expected. After drilling 12 wells and numerous lessons learned, the furthest extended reach well in the history of Brazil was attempted and successfully completed.
The Pol-O wellbore was drilled to a total measured depth of 6,489 m (2,429 mTVD) and a vertical section step out of 5,615 m. This wellbore was and continues to hold the record for furthest reach wellbore in the history of Brazil.
In addition to obtaining this extended reach record, Polvo also attained the record of fastest 24 hours drilling in an 8 ½" hole with 1,610 m in 24 hours. To obtain this drilling record, it was not only critical to have high on bottom ROP, but also to optimize connection time. The high torque connection helped to achieve this fast connection time and also prevented any drill string failure.
Having drilled over 100,000m of total hole in highly deviated wellbores using the same drill string, there has not been any twist-offs or back-offs on the Polvo project.
By being able to drill these further reach wellbores successfully and more economically, the Polvo Platform has proved up further reserves that can be produced without requiring installation of another platform or subsea tiebacks. The rig is not limited by connection strength and plans are in place to improve the top-drive to deliver more torque, while staying with the same double shoulder connection size.
A Case Study : Innovative Open Hole Well Completion Provides Superior Results in Tigh Gas Formation in Jilin District, China
Authors: Feng Wang , Liu Changyu , Zhang Yingan , Wang Yong , Liu Hai , Tong Ku Ka 
Published: May 2016

Abstract
Drilling of horizontal wells has increased steadily over the last few years in China on land. As technology has developed, operators have seen the economic and production benefits of drilling horizontally 1, 2. In the Changling gas field, the Deng Louku formations are primarily low porosity (average 5.2%) and low permeability (average 0.17md) tight sand. Typically, wells in this area are drilled vertically and completed with cemented casing. Proppant fracturing was necessary to produce the well economically due to the low permeability nature of the formation. However the production results from the conventional vertical fracturing completions were not very promising and most of the wells experienced rapid production decline once they were put on production. Thus it became crucial to find an engineering solution to effectively unlock the reserves and obtain sustained long term productivity.
Multistage fracturing of the DP2 horionatal well is a milestone for the operator due to:the deepest, and most stages in a single horizontal well in a tight sand formation in China was completed and fractured;the biggest fracturing job for a single well in terms of proppant and fracture fluid volume was successfully pumped continuously by first time application of the precise continuous mixer (PCM) in China;an innovative multistage fracturing design workflow was developed to optimize the horizontal well completion design including several disciplines: geology, reservoir modeling and fracturing.
This workflow was set as the standard design process for multistage fracturing design in the field.
The DP2 horizontal well was completed in ten stages in the 837 m openhole section and the ten fracturing stages were pumped continuously in 3 days. The PCM was used to improve the fracturing operation efficiency. A total of 1425 tons of 30/50 proppant was successfully placed into the formation using 4870 m3 fracturing fluid. The well produced 320,000 m3/day initially and was stabilized at 180,000 m3/day with 20 MPa wellhead pressure, which is 5 times higher than the average offset well.
The application of real time hydraulic fracturing monitor technology helpped to verify that the optimized fracture half-length was achieved, and to adjust the fracturing schedule in real time for the second stage.
New Hybrid Bit Exceeds Expectations in Challenging Application in Tarim Field, China
Authors: Nicholl Denise , Garcia Alexis , Barocio Hector , Sha Dennis , Jian Zhou 
Published: May 2016

Abstract
The existence of hard, interbedded formations often prove to be very damaging to conventional polycrystalline diamond compact (PDC) fixed cutter bit designs, and as a result, may require additional trips to replace the bit for insert roller cone or impregnated diamond. This can represent significant additional drilling costs for the operator, equating to very high costs per foot if the remaining section to be drilled is short. The challenge is to maintain a low cost per foot, through the use of a bit design which is both durable enough to drill the desired interval, at the best possible penetration rate.
This paper describes the development of a new innovative drill bit technology that fuses two existing fixed cutter materials using a unique design philosophy that allows for greater versatility in drilling a wider range of interbedded, difficult to drill lithologies that are not typically drilled entirely with PDC bits. This novel design philosophy includes optimized cutter placement allowing engineered exposure of diamond impregnated mix applied in critical areas of the bit for added durability.
This development project was initially targeted for the sub-Saharan region in the Congo, where the existence of a conglomeratic interval at the bottom of the section prevented to reach total depth (TD) with fixed cutter bits, having to end with roller cone insert designs. In its first trial, the new design drilled three times the interval of the best offset with a 34% improvement in rate of penetration (ROP).
Applications in different regions of China were soon identified, resulting in a challenge to design for a new hole size with various drive types; the results of which are detailed in this paper.
A Comprehensive Formation Evaluation Method to Make the Fracturing Decision: A Real Case Analysis from a Low Permeability Formation in Jungger Basin of China
Authors: Wang Ben-Cheng , Nie Ren-Shi , Xu Jiang-Wen , Wei Shao-Bo , Hu Guang-Wen , Zhang Jun-Ming , Feng Meng 
Published: May 2016

Abstract
Low permeability formation is the main exploration objective in China. Too much misjudgments of fracturing operation would tremendously increase the cost of exploration. We studied a method to estimate the well productivity for a Permian low permeability formation in Junggar Basin of China. Firstly, we made a statistical analysis to the lithology according to logging data and divided the lithology into 7 categories. We developed a set of standards to mark the seven categories. Secondly, we made a statistical analysis to 6 parameters of physical properties, such as porosity, permeability. We also developed a set of standards to mark the physical properties. Thirdly, we made a statistical analysis to DST data and divided the log-log curves of DST into 5 categories. We defined a pressure recovery rate that can reflect the formation energy status and analyzed the characteristics of the pressure recovery rate for different category DST curves. We marked the 5 categories DST curves and its pressure recovery rate. Fourthly, we made a mathematical statistics to the relationships of fracturing productivity with static and dynamic parameters, including pressure recovery rate, sand volume and fluid volume of fracturing. We obtained the productivity prediction equations by using multiple nonlinear regressions to static and dynamic parameters. Fifthly, we needed to use the method of the above 4 steps to mark the lithology, physical properties and DST of a new well and estimate productivity. Finally, we made a suggestion of fracturing to the new well. We applied the comprehensive formation evaluation method to 12 new wells of the Permian low permeability formation. Compared with the real oil-testing results after fracturing, the judgment accordance rate is 75%. The researched method can be generalized to other low permeability formation.
3D Seismic Attributes as Exploration Tools: A Case Study from the Late Jurassic Hanifa Formation in Saudi Arabia
Authors: Liu Libin , Kharji Mohammed , Chatterjee Himadri S. 
Published: May 2016

Abstract
The Arabian Gulf, in Saudi Arabia, is a mature petroleum province. As exploration moves from structural concepts to the stratigraphic domain, identifying petroleum system elements in areas with limited well control becomes imperative to cost-effective exploration. Explored areas are blessed with reliable datasets (most significantly well data) that records subsurfacerock properties. In exploratory areas with very sparse well control, seismic is the most appropriate data set currently available for approximating rock properties. Therefore, finding reliable seismic attributes that correlate to rock property variations in well logs holds the key to exploratory success.
This paper presents the results of a project undertaken to identify seismic attributes that differentiate between source and reservoir facies within the carbonate Hanifa Formation in the Eastern Province of Saudi Arabia. A detailed analysis of wireline logs from wells suggests that rock properties like velocity, impedance, Lambda Rho and Mu Rho are higher in carbonate source facies under consideration than their reservoir counterparts. Impedance computed from seismic inversion is found to be in consonance with that derived from wireline log data. Projected facies are found to fit predictions of the geological model in wells in the study area. Mapping of impedance in the 3Dseismic volume helps carry the interpretations from the known to the unknown. Acoustic impedance, derived from seismic inversion, thereby offers promise as a tool for identification of petroleum system elements in areas with very sparse wells.
Cementing Through Capillary Tubing to Meet Regulatory Requirements: A Novel Approach for Plug and Abandonment
Authors: Wilde Jason , Ellis Todd 
Published: May 2016

Abstract
Capillary tubing has traditionally been used for various downhole chemical treatments applied to enhancing fluid loading, treating corrosion and scale buildup, and preventing paraffin and emulsion formation. Capillary tubing provides an advantage over coiled tubing due to its lighter weight, smaller footprint, mobile structure, faster running speeds, and more economical costs. One drawback however, is the increased friction pressures when pumping abrasive fluids. Typical capillary tubing is sized from ¼ to ¾ in. OD versus the more common coiled tubing, which ranges from 1 to 3 ½ in. OD. Therefore, the use of capillary tubing for cementing operations has not been considered until recently.
This paper will feature a project in Australia where a capillary unit was employed to abandon a well with cement, while concurrently installing downhole pressure gauges to comply with local regulations. The cement design criteria along with two case histories will be described, and lessons learned will be evaluated.
Data that has been collected through the various jobs will demonstrate that current simulation software will need to be modified to match pressure outputs witnessed in the field. A comparison of simulated versus actual job pressure data has shown as much as a 70% friction reduction in actual pressure readings. The witnessed pressure values are shown to be consistent over several operations; therefore a theoretical correlation can be drawn so more realistic values can be simulated in the future. Additionally, slurry designs which were proven successful and operational considerations for improved job quality will be discussed.
This paper will discuss two case histories in which capillary tubing was used for the first time in Australia. Methodology, limitations, and future improvement possibilities will be discussed in detail throughout this paper.
Multi-Tubular Corrosion Inspection Using a Pulsed Eddy Current Logging Tool
Authors: Rourke Marvin , Li Yong , Roberts Glyn 
Published: May 2016

Abstract
Tubular inspection can be split between direct measurements such as caliper logs or downhole video observation and Electromagnetic (EM) methods that measure properties sensitive to pipe thickness, with wall thinning associated with corrosion and other pipe defects. Various EM methods have been reported over the years often initially for pipeline inspection and then adapted for downhole well monitoring. These methods include Magnetic Flux Leakage (MFL) and Eddy Current (EC) measurements. Early EM methods were single frequency but later developments include multi-frequency. In this paper we report an emerging technique called Pulsed Eddy Current (PEC) which is inherently multi-frequency and in time domain is radially sensitive which enables inspection of multiple tubular thicknesses. Most inspection techniques including some EM methods are only capable of inspecting the inner most tubular or only the total thickness of multiple tubulars. However, a PEC tool can measure separate thicknesses of both inner and a second tubular. This allows quantitative corrosion evaluation of casing without removing the completion tubing.
The paper covers a theoretical review of the PEC technique and development of a fast forward analytical model tied to experimental data acquired with an actual logging instrument. The fast forward model is used to ensure optimum tool design and allows development of an inverse model which realises quantitative evaluation of the corrosion within multiple tubulars from field data.
Development Optimisation of a Marginal Oil Field in Bohai Bay China - Integrated Solutions to Overcome Challenges in Offshore Horizontal Well Construction
Authors: Nie Chaomin , Zhao Yongsheng , Tan Lv , Jia Yong , Zhai Gang , Halomoan Parlindungan Monris , Hui Xu Chong , Yong Wang , Fei Wang , Jianyi Dong 
Published: May 2016

Abstract
A total of nine horizontal wells including one injector well were drilled to cover the small, 9 km2, oil-bearing area of a marginal oil field that is isolated by secondary faults and stratigraphic depositional borders in Bohai Bay, China.
A pilot study showed that the reservoirs are distributary channel sands of a shallow water deltaic depositional system. Seismic inversion indicated that the sand properties and connectivity vary dramatically across the field. A multiple-aquifer system was apparent, and the gas/oil contact (GOC) and oil/water contact (OWC) levels were unknown. Furthermore, the only well control was from three vertical exploration wells and two directional offset wells.
An advance distance-to-boundary well placement technique using azimuthal deep directional electromagnetic logging-while-drilling (LWD) technology was applied to overcome these challenges and to enhance reservoir understanding. A multifunction LWD formation evaluation tool was deployed to evaluate fluid properties where the top gas might occur. In addition, a rotary steerable drilling system (RSS) was assembled to achieve drilling efficiency and smooth trajectory control.
One injector well and eight producer horizontal wells were precisely placed in optimum position for injection and drainage with a 100% success rate; one producer horizontal well was retracted while another producer well was added based on finding definite GOC and OWC levels. Increasing the drilling penetration rate and avoiding adjustments following reservoir exits led to a 60% improvement in drilling efficiency, which is equivalent to a cost savings of USD 32 million. Production from these horizontal wells surpasses the set production target by 30%, with extremely low water cut. The integrated LWD, well placement, and RSS solution optimized the marginal oil field into a much more economic development oil field.
Successful Development of Thin Zones: Challenges and Strategies
Authors: Al-Julaih Ali , Taibah Obai 
Published: May 2016

Abstract
Thin reservoirs that are only a few feet in thickness present a clear challenge to development specially when coupled with fractures, lateral heterogeneities, and structural uncertainties. This paper discusses the challenges associated with the development of a thin zone located at the top of a carbonate reservoir as well as the strategies implemented to overcome these challenges and develop the zone successfully.
Due to the lower rock quality when compared to the underlying zones and extreme thinning, this zone could not be produced through the conventional vertical wells historically. Through the strategic monitoring program implemented in the field, an opportunity to place direct production from this zone has been identified specially in the mature areas of the field where the lower zones are fully swept after decades of continuous production whereas a thin zone at the top of the reservoir is unswept. Capitalizing on this opportunity, a strategic development plan has been initiated. This plan calls for placing horizontal laterals in this zone utilizing recently developed fit-for-purpose well placement and completion technologies.
To successfully develop this challenging zone, several strategies have been implemented. First of these was strategic well planning where a systematic methodology was implemented to evaluate and develop this zone. The most promising target areas were located through comprehensive evaluation of the area, with detailed geological modeling. Secondly, advanced geosteering with a rotary steerable system (RSS) has been utilized to efficiently place laterals in the upper lobe of the targeted zone. Advanced completions, using inflow control devices (ICDs), were utilized as a fit-for-purpose to mitigate the counter effect of fractures and/or pressure differences across the horizontal section. The development program has been very successful in yielding significant production gains.
Sour Gas Amine Filtration Enhancement
Authors: Khan Asif 
Published: May 2016

Abstract
Saudi Aramco Gas Operations can process over 8 BSCFD of gas. Diglycolamine (DGA) is the most widely used Amine in gas treatment facilities. Similar to other types of amines such as monoethanolamine (MEA), diethanolamine (DEA) and methyl diethanolamine (MDEA), the performance of DGA is mainly reduced by accumulation of contaminants, e.g. suspended solids, hydrocarbon liquids and degradation products. Foaming, solvent loss, fouling and other operational problems are associated with DGA contaminants in high-pressure (HP) DGA systems. Low pressure systems generally have more stable performance with less operational issues. These issues are generally managed by anti-foam injection, fresh solvent addition and installation of mechanical filters.
The gas treatment system is equipped with inlet gas filtration and amine filtration to reduce the contamination level in DGA, e.g., suspended solids, pipe corrosion due to aging and hydrocarbons. Slug catchers remove the bulk of liquid in the gas. Three phase separators with coalescing element remove liquid aerosols and solid particulates. DGA filtration consists of a pre-coat filter (1 micron rating) and a mechanical filter (5 micron rating) installed on a slip stream.
The pre-coat filter consists of diatomaceous earth (diatomite or kieselguhr) coating material bonded to a mechanical screen or leaf. The filtration media is chemically inert and contain a silica skeleton. A pre-coat filter removes suspended solids, contaminants and other particulate matter; to build a pre-coat primary filter medium layer to be deposited on the basic screen. The correct cake buildup is essential for optimum filtration results.
Sometimes pre-coat filter performance is not up to a satisfactory level due to the quality of cake build up. Gas plants are putting extra efforts to maintain gas treatment units to control amine quality.
Application of Reservoir Navigation with Boundaries Detecting Technologies in Lufeng Oilfield, South China Sea
Authors: Yiling Hao , Shuquan Xiong , Yiming Wu , Yongjun Fang , Chuyin Li 
Published: May 2016

Abstract
Reservoir Navigation with Boundaries Detecting Technologies, Baker Hughes AziTrak™ azimuthal navigation can achieve maximum standoff to oil/water Contact and minimum standoff to shale roof, increase exposure to reserves and identify future opportunities. CNOOC, one of China's major operators recently used this servicesdrilled 7 wells with 3570 m lateral section in the Early Miocene Zhujiang sandstone formation while maintaining a challenging distance of 0.8 m from the roof of the formation and safe standoff above bottom/boundary water.
"The ability to drill accurately within the zone was impressive, and the ability to also drill it fast was remarkable, with exact wellbore placement, you can extract more value from mature field" said the client's management representative. In the demonstration effect of this field, more and more fields of CNOOC are taking the Reservoir Navigation with Boundaries Detecting Technologies to facilitate simplified reservoir navigation decisions for increasing efficiency, saving rig time with early oil-water contact-zone detection, driving maximized hydrocarbon recovery through precise wellbore placement. This paper will be focusing on above cases to study.