bluuebunny/crossref_metadata_2025_split huggingface dataset:
Innovative Well Cementing Applications by Using Large Particle Sizes of Cement Additives
Authors: Doan Angela , Brandl Andreas , Vorderbruggen Mark , Leonard Daniel D. 
Published: October 2015

Abstract
Water-soluble cellulose based polymers such as hydroxyethyl cellulose (HEC), methylhydroxyethyl cellulose (MHEC), and carboxymethylhydroxyethyl cellulose (CMHEC) are commonly used additives to control important cement slurry properties like fluid loss, free fluid, and slurry stability. They typically hydrate quickly after contact with the mix water resulting in instant slurry viscosification and potential mixing difficulties especially at higher loadings. Adding cement dispersants to the cementing system design can facilitate slurry mixing but this does not always work out as expected. Sometimes incompatibilities between the dispersant and the other additives result in even more difficult slurry mixing. Furthermore the addition of dispersants to compensate mixing problems can enhance thermal thinning leading to severe settling issues once the slurry is exposed to the elevated downhole temperatures in the wellbore.
To overcome these challenges, the use of large particle size cement additives to lower the surface mixing viscosity and the effect of important slurry properties were studied. The cement fluid loss, free fluid control, and slurry rheology performance of large particle size polymeric additives were evaluated in cement slurries. Different particle sizes for polymeric additive were tested in assorted cement densities and temperatures. Cement testing procedures, lab test results, and a case history is presented and discussed.
The study demonstrates that the hydration of the cellulosic polymers is delayed as particle size of polymeric additives increases. It could be concluded that the use of larger size cellulosic polymers greatly facilitates slurry mixing, requires less mixing energy or reduces slurry mixing time, and results in a lower initial slurry rheology without negatively affecting other slurry properties (in some cases the fluid loss performance was even significantly improved).
Experiment and Simulation Research on Hydraulic Fracture Propagation Characteristic under Interface Layer Influence
Authors: Kangxing Dong , He Liu , Suling Wang , Minzheng Jiang 
Published: October 2015

Abstract
Key factor to develop shale reservoirs effectively is formed stimulated reservoir volume (SRV) of complex fracture network. When hydraulic fractures intersect with interface layer or natural fracture, fracture may slip along the interface, that provides a condition for the formation of fracture network. Bi material shale reservoir fracture mathematical is established in this paper, the critical conditions of shear sliding was studied by using elastic theory. Physics experiment is constructed by using the similarity criterion of the interface layer effect on hydraulic fracture extension, the influence of horizontal differential principal stress, interface friction coefficient and rock tensile strength on the fracture propagation is studied by hydraulic fracture experiment. This paper established finite model of bi material shale reservoir by using RFPA2D software, the influence of horizontal differential principal stress, interface friction coefficient and rock tensile strength on the fracture propagation is simulated. Analysis results show that: In the condition of low horizontal differential principal stress, low interface friction coefficient and high differential rock tensile, shearing slippage damage tend to happen, the fracture will continue extend along the direction of the maximum principal stress when it meted flaw after extend along the interface. On the contrary, fracture tend to cross the interface. This research has important theoretical value and practical significance to network hydraulic fracturing of shale reservoir.
Development of a Trilinear Flow Model for Carbon Sequestration in Depleted Shale
Authors: Chen Z. , Liao X. , Zhao X. , Lv S. , Dou X. , Guo X. , Li L. , Zang J. 
Published: October 2015

Abstract
While many researchers are trending to seek the conventional geological sequestrations for CO2 storage, like saline aquifers, depleted conventional hydrocarbon reservoirs, and unminable coal seams, only a few are interested in depleted shales for safety and economic reasons. Thus, for reservoir engineers, lots of work needs to be done to better this situation. First and foremost, it is an urgent issue should be settled how to estimate the CO2 storage capacity in depleted shale.
In this paper, a new analytical method to estimate CO2 storage in shale wasdeveloped. First, a trilinear flow model was proposed for the injection well, namely a multiple fractured vertical well (MFHW), at a constant injection rate. The model incorporated with multiple mechanisms including Knudson diffusion, gas adsorption, and effect of stress-sensitivity. Then, the transient pressure solution of injection well is solved by applying mathematical methods. Subsequently, CO2 storage capacity was evaluated according to the transient pressure performance of injection well. After that, model verification as well as sensitivity analysis was conducted. Finally, we applied the proposed method into a case derived from the New Albany Shale, which has been proved to be a promising candidate for CO2 storage.
The results show that a good agreement exists between our analytical results and these numerical solutions. The average difference is about 2.57%, which shows our methodology is reasonable. Further, it only takes about 10s CPU times with 100 time step by employing the proposed approach to estimate the CO2 storage capacity of the study area in the New Albany Shale, which indicates the new approach is rapid. Additionally, results of sensitive analysis show that as stress-sensitivity coefficient, adsorption index, and Knudsen diffusion coefficient increase, CO2 storage capacity increases. As storage ratio increases, CO2 storage capacity decreases.
This meaningful work provides a new angle on estimation of CO2 storage capacity, which is beneficial to exploit the residual depleted shale reservoirs as well as cut CO2 emission.
History Matching with Ensemble Kalman Filter Using Fast Marching Method in Shale Gas Reservoir
Authors: Leem Jihun , Lee Kyungbook , Kang Joe M. , Park Yonjun , Park Jihye 
Published: October 2015

Abstract
In case of shale reservoirs, there are lots of uncertainty parameters: matrix permeability, fracture permeability by hydraulic fracturing, enhanced permeability surrounding fractures, fracture half-length, vertical enhanced ratio, horizontal enhanced ratio, and porosity. Reasonable uncertainty quantification enables us to predict shale reservoir performance. Ensemble Kalman filter (EnKF) is one of the most reliable history matching method. However, EnKF has the limitation of simulation time because each prediction step requires forward simulation as the number of ensemble members. Larger size of a field is simulated, much simulation time is consumed. Fast marching method (FMM) is able to reduce simulation time and shows reliable result of shale gas fields compared with other simulators. Therefore, we ropose the concept of unification of EnKF and FMM for reliable and fast.
To validate the advantage of the proposed method is compared with EnKF using a conventional forward simulaotor. Also, the proposed method is coupled with distance-based generalized sensitivity analysis (DGSA) to select sensitive model parameters. FMM-EnKF using selected parameters is useful when it is difficult to obtain reservoir uncertainty information. The three methods, the standard EnKF, FMM-EnKF using all parameters, and FMM-EnKF using selected parameters, are compared by history matching time, distribution of uncertainties, and cumulative responses.
The standard method and the proposed method shows decline in width of uncertainty after history matching. However, the proposed method completes history matching faster than the standard EnKF. Most of all, the proposed method using selected parameters decreases the width of cumulative responses compared with the proposed method using all parameters. Therefore, this method is going to contribute the section of history matching and prediction of future production.
Extracting Lessons Learned of 35 Water Shut-off Jobs in Mature Fields to Improve Success Ratio of Water Shut-off Job
Authors: Permana D. , Ferdian G. , Aji M. , Siswati E. 
Published: October 2015

Abstract
Increasing water production in a mature field means an increasing burden of operating cost because that water production must be processed and treated before it is discharged or injected1. One common solution to overcome this problem is conducting water shut-off jobs which consist of mechanical and chemical water shut-off. Mechanical water shut-off is preferred to be carried out over chemical water shut-off because of lower costs. An example of mechanical water shut-off is using cup packer, squeezing-cement, and reperforating over a shorter interval.
In Central Sumatra, there were approximately 35 mechanical water shut-off jobs executed from 2010 – 2012. Those jobs were varied from mature fields having different geological conditions, recovery mechanisms, drive mechanisms, and operating-rate conditions which may be influencing the rising of current oil water contact (COWC).
Based on the completed water shut-off jobs, some lessons learned were to have perforation interval above current oil water contact (COWC), have good historical water shut-off performance at surrounding wells, have good production performance at surrounding wells, have good structural location, and have by-pass oil identified from CO/RST log if it is below COWC. Those lessons learned will be applied to upcoming water shut-off candidates.
This paper further explains of some lessons learned which will be useful for selecting candidate of water shut-off jobs and compares the result of water shut-off jobs after implementing lessons learned which significantly increased its success ratio and oil gain.
The Success Story of Light-North Area of Roger Block: Continuous Exertion to Increase Electrical Submersible Pump Performance through Rectifying Design Process to Resolve MDSS Problem
Authors: Dewi Cintani Kusuma , Rahman Fatkhur , Maulana Prapta 
Published: October 2015

Abstract
Mud-Debris-Sand-Solid (MDSS) is identified as second top contributors for 2011-2012 ESP failures in Light-North Area, a potential light-oil-field in Roger Block. It caused 20% total failure, with sand and debris as top contributors. Loss Production Opportunity is around 39 MBO from total 25 cases; rig services for reactivation costed averagely 12.5 MUSD/job. It's seen necessary that workflow process in pump design must be improved to treat MDSS issue more effectively to avoid reoccurrence.
The existing design process possesses numerous aspects to be considered. The team decided to place more emphasis on items that might give high impact in enhancement. Rectified workflow design process is then generated, this present as standard guidance on defining mitigation, proactive, and reactive recommendations. All recommendations are managed by prioritization based on the new-workflow with less effort yet giving big impact. As part of the study, 8 wells with historical MDSS and last run-life less than 180 days were selected to be monitored. Once experiencing down, the new-workflow is then applied.
Every mitigation step in this work is obviously not new, but executing them in a random sequence can only waste time, effort and certainly money. With the continous drop of crude price, proper mitigation is a simple formula to optimize our resources and hence results in an efficient yet safe operation.
Novel Fracturing Fluid Significantly Increase Production in Sulige Tight Gas Field
Authors: Yang Zhanwei , Yang Lifeng , Duan Yaoyao , Wang Yonghui , Tian Zhuhong , Lu Yongjun 
Published: October 2015

Abstract
Sulige gas field located in Ordos Basin is the largest gas filed in china. Eastern block of this field which consists more than 1000×104 MMscf geological resources belongs to tight gas reservoir. Due to low gas saturation, less than 10% porosity, around 0.05 mD permeability and below 0.85 pressure coefficient, stimulation treatments is necessary in order to get economic production. Development speed of this block had been seriously affect because of Significantly lower single well production than other parts of the Sulige gas field. Low concentration crossed-linked guar fracturing fluid is now commonly used in this area. As small size pore throat, high clay content and water lock, this gas deposit is sensitive to treatment fluid, thus the flowback time of fractured well is very long and production is generally low. In this paper we introduce a new fracturing fluid which can be crossed-linked in acidic water-based fluids. This fracturing fluid contains a kind of cellulose, which is completely soluble with no residue. Cellulose had been used as addition agent in drilling and completion fluid twenty years ago, therefore application range was greatly limited as bad performance stability. New cross-linked agent and additives solved this problem. Because of being compatible well with the reservoir fluids, the damage of fracturing fluid is relatively low. Proppant carrying capacity of this new fracturing fluid can be compared with low concentration crossed-linked guar fracturing fluid. The new fluid has been used in 6 vertical wells, which have 100% treatment success-rate and 8.6×104m3/d average production rate. Comparing with the nearby wells which had the same pay formation and were fractured with the similar fracture treatment scale by low concentration guar fracturing fluid, the flowback time was shortened by 53% and gas production was doubled. In conclusion, this new fracture fluid can reduce treatment time, cost and increase gas production.
A Structured Energy Architecture Performance Index Approach in Managing the Challenges of Indonesia's Energy Sector
Authors: Budiarso Budiarso , Adrian Herman , Gunawan Widy , Nalle Herbert , Pramudita Reza , Tanuwijaya Ryan 
Published: October 2015

Abstract
Since the industrial revolution in 18th century, people were always looking for more economical, more sustainable and – recently put into concerned about – more eco-friendly energy supply to fuel up the world economic growth. However the fact showed that the energy we consumed even became less affordable, less secure and less environmental sustainable for the last decades.
World Economic Forum collaborating with Accenture formulated Energy Architecture Performance Index (EAPI) to provide more structural approach in understanding the condition of each country's energy system. Energy Architecture is defined as the integrated physical system of energy sources, carriers and demand sectors that are shaped by government, industry and civil society.
Driven by the boundary constraints of economic development, geography and prosperity, countries are striving to find new and innovative ways to meet the demands of their energy system. The transition pathway from the current Energy Architecture to the new will look different for each country, with energy system objectives planned according to the trade-offs and complementarities surrounding the core imperatives of every energy system: managing risk to energy supplies while ensuring a country's economic, social and environmental well-being.
Estimation of Time of Peak Gas Production in Coalbed Methane Wells using Production Data Analysis
Authors: Salmachi Alireza , Darby Jake , Yarmohammadtooski Zahra 
Published: October 2015

Abstract
For coalbed methane (CBM) wells with rising gas production, time to reach peak of gas production and peak gas rate are two fundamental features of a production profile. This paper investigates the time of occurrence of peak of gas production in CBM wells using production data analysis (PDA).
The methodology is simple and requires gas rate and flowing bottom-hole pressure (BHP) data. Signatures of time of peak gas production are obtained using time derivative of square of BHP over gas rate. Signatures are obtained for constant and variable bottom-hole pressure operational constraints. Derivative of square of BHP over gas rate with respect to time is calculated for observed production data. Then, plot of this derivative versus production time is constructed for the CBM well. Finally, the plot is extrapolated to a time at which the signature of peak production appears. This time is estimated to be the time of occurrence of peak of gas production. The production data for a CBM well in San Juan basin is analyzed using this technique to demonstrate the signature and the estimation of time of peak gas production.
The accuracy and correctness of estimation depend upon quality of production data, goodness of fitted functions used in this approach, and time interval between time of peak gas rate and observed production data. The signatures of time of peak production introduced in this paper can contribute to production forecasting of the negative decline portion of the production profile of CBM wells.
Economic Success in Complex Channel Sand Reservoir Development Driven by New Technology
Authors: Yang Liuhe , Zhao Yongsheng , Nie Chaomin , Guo Xijia , Sun Guoqing , Yu Xiaoning , Wang Fei , Xu Chonghui , Fu Zairong , Chen Chengqian , Xu Tianyun , Wen Xin 
Published: October 2015

Abstract
BZ29-4 is a new development field located in the southern part of Bohai Bay which is the main offshore block for CNOOC (China National Offshore Oil Corporation). Distinguished from others, BZ29-4 is featured by braided fluvial sand deposition and multiple post diagenesis tectonic movements. Reservoir's scattering distribution and micro faults' fully deployment become big challenges for field development. Restricted by technic capacity and budget management, BZ29-4 was kept as a reserved field in operator's strategy.
According to CNOOC's objective – obtaining 35 million m3 production in 2015, and scientific innovation, a new drill campaign is proposed in 2012. Several new technology is adopted. Boundary detection technic provides detailed profiles overcoming the difficult about unclear oil/gas and oil/water contact position. By following the environment requirement, a new sourceless density/porosity measurement is applied. Rotary steerable system demonstrates high adaptability in disconnected and isolated sand bodies and eminently improves drilling safety. These technology with advance data transition platform, multiple discipline research staff involves in the drilling, delivering real time support and reducing the gap between study achievement and execution.
Through considerable data assessment and feasibility study, an innovative dynamic exploration strategy is used in this development project. Instead applying the whole suit technic in every well, the combination of new technology is optimized according to each well's particular challenge. Besides, well deployment and plan trajectory are timely adjusted in assistance of the fresh drilling result. By this means, the economic portfolio for BZ29-4 is significantly rationalized and 8.85 million USD has been saved in field development stage.
Until the end of 2013, 15 horizontal wells has been drilled in this field. With the new technology application, net-to-gross (NTG) is promoted to 100% and drilling efficiency increases 80.9%. After all these wells are in production, the daily output reaches to 295t/d exceeding operator's expectation by 51% and the recovery factor elevates to 29.9% leading in all CNOOC fields.
Integrated Offshore Mature Field Revitalization in Asri Basin, North Business Unit Area, Southeast Sumatra, Indonesia
Authors: Waskito Lucky Bagus , Widiatmo Reza , Gunawan Heri , Pengxiao Sun 
Published: October 2015

Abstract
Asri basin has been on producing since July 1989, currently there are 9 fields has been developed with strong water drive reservoir driving mechanism characteristic. Peak production was 196,000 bopd, presently producing 34,000 bopd with water cut of 99 %. Challenge faced in the studies had to deal with mature reservoir, declining production, depleted reservoir pressure, unrealistic recovery factor and the need to enhance asset value. Beyond that complexity, commercial challenge in rejuvenating the field becoming more critical due to falling oil prices.
This paper present how integrated evaluation of mature offshore oil field performance and investigated various scenarios could add more value to the asset. Water flood, water shut off, and single field revitalization project has been implemented and it shows satisfaction result in reducing and maintaining production decline rate even increasing oil production volume. Recommendations also made to sustain and gain oil production by implementing successful projects to other field and also trying to implement Polymer Injection pilot project in Indonesia.
The important thing in revitalizing a mature field is to define a customized asset evaluation approach to managed large amounts of data and identify the most important mechanisms in creating value-added solutions, while minimizing costs. The team captured this through innovative systems planning and operation, displacing the traditional lab-to-field R&D search in that multiple options were generated from within functional technology contributions.
As expected, the results of full project implementation are satisfying. Depleted reservoir problem in major field producer has been solved by water flood project, the pilot project has been conduct in 1999 and shows great result in increasing oil production rate, within 2 years the oil production rate increase from 2,000 bopd to 12,000 bopd. Another project has been implemented in this major field is facies re-analysis, from this analysis new map are created, therefore new point of view can be extracted to support more comprehensive analysis, and the new analysis are very useful to gain oil production. Marginal field also part of the revitalization program in Asri Basin, in 2012 rejuvenation project has been conducted, and the result shows 4 times oil rate incremental, from 264 bopd to 908 bopd. One of other successful project is water shutoff, 2 wells are implemented for this project, and it can reduce water cut up to 17%, from 99% to 82% water cut. Those successful projects will be implemented for other field in Asri basin North Business Unit Area to Sustain and Gain Oil Production Rate.
Optimum Competency Development and Career Path - Skillmap Approach
Authors: Nishi Masatoshi , Yoshida Takeshi , Yasuda Chika 
Published: October 2015

Abstract
An Accelerated competency development is one of the essential factors to achieve and sustain the medium- to long-term vision of INPEX. After intensive reviews and discussions, a skillmap based development approach had been selected and implemented especially targeting young technical professionals to enhance the company's overall technical capabilities. This paper describes the key success factors of our Skillmap set-up approach and its implementation procedures.
The internal discussion concluded that we required "own" style of competency development scheme rather than utilizing a ‘ready-made" scheme or contracting out. Three key points of our approach are highlighted as follows. Job matrix and skill matrix: Two matrixes were created to evaluate the work experiences and technical capabilities respectively for the optimum development plan.A face-to-face approach: This is our core approach of communication, to build strong relationship between young and senior professionals.A dedicated competency development support team, so-called "Skillmap team", leads the entire process proactively.
The approach was implemented nearly two years ago and over 150 young professionals have experienced the processes.