bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solving Unexpected Sanding Issues in HP/HT, Tight-Sandstone Keshen Gas Reservoir, Western China
Authors: Yang Xiangtong , Huang Yongjie , Zhang Yang , Qiu Kaibin , Fan Wentong , Pan Yuanwei , Xu Guowei , Xian Chenggang 
Published: November 2017

Abstract
Keshen is a high-pressure/high temperature (HP/HT) tight-sandstone gas reservoir with reservoir pressure over 110 MPa and temperature over 175°C. The sandstone is very hard, with unconfined compressive strength (UCS) greater than 100 MPa. Given the HP/HT nature and natural fracture system in the reservoir, with aid of stimulation, many wells produced at a very high rate with the mean value exceeding 500,000 m3/d. In the last few years, many production wells in this reservoir experienced severe sanding issues that contradicted the conventional understanding that sanding would not occur in such hard rock. The sanding wells exhibited large fluctuations of production rate and wellhead pressure, erosion of chocks and nozzles, and eventually major or even complete loss of production. A solution to address the sanding issues was urgently needed because the sanding issues had caused a major decline in production and resulted in significant economic loss.
Due to the unconventional nature of the sanding issues, the typical sanding prediction methods based on solely on evaluating rock failure were not adequate to reveal the underlying sanding mechanism and develop a viable operational solution to address the sanding issues. To this end, a new workflow was formulated and applied to this study. The workflow started with detailed data mining on the massive amount of drilling, completion, stimulation, and production data from this reservoir to investigate possible relationships of drilling practices, completion options, and production schedules to the occurrence and severity of sanding issues. The analysis revealed that downhole flow velocity and production drawdown were the two major controlling factors in the occurrence of sand production. Further geomechanics simulation and particle migration simulation with a multiphase dynamic flow simulator confirmed that the production drawdown would cause failure of the rock near the wellbore and the gas flow could transport the sand debris to the wellbore and lift it up to the surface. In addition, the fluctuation of production rate was caused by blockage due to accumulation in the wells and production tubing of sand particles that were flushed out after downhole pressure buildup.
Based on the analysis, the threshold of flow velocity and the threshold of drawdown were identified, and these thresholds can be used in the reservoir management to address the sanding issues.
The experience in Keshen shows that sanding is possible in HP/HT high-productivity sandstone gas reservoirs, even in extremely hard formation, which overturns some prior conceptions on sanding. The information shared from this paper could bring up the attention of those operating similar HP/HT tight sandstone reservoirs around the world.
Applying Edge Computing to Autonomous Well Control
Authors: Pitcher Jason , Pry Mike 
Published: November 2017

Abstract
In production operations, a lot of effort has been devoted to monitoring well head and flow line parameters. Connecting sensors to monitoring systems, collating, and transmitting the data off site for manual or automated review requires infrastructure build out and processes developing to analyze and action the data, consuming additional resources. The concept of edge computing, moving the analysis and decision closer to the well is a challenging problem which requires the addition of controlling elements. The objective is not just to monitor the conditions, but also to take action based upon the observations without unnecessary intervention.
This paper introduces a new method of closed loop production control, integrating production tree master valve, emergency shut down system and choke management into a single automated, autonomous system. By implementing microprocessor control at the wellsite, basic management functions can be automated with sequencing to mitigate risk of procedural errors, improve well integrity, and minimize downtime. The key elements of such a system comprise of master valve actuation, wing valve actuation and production choke actuation linked by a single co-dependent system that can perform condition based monitoring and self-diagnose system issues.
A discussion of the design and function of the method, with due regard to limitations, best practices and workflows will be demonstrated, providing an examination of the results of design experiments. The potential for further implementation is examined as well as highlighting operational differences vs current technology that deliver value to producers and operators.
Expanding the capability of wellsite autonomous control to address operational concerns and reduce operational costs is within the reach of technology that is integrated into monitoring systems, moving the decision point closer to the well. With a proven ability to monitor and action analyses, communicating the results of the action for operational status updates substantially reduces the need for large bandwidth infrastructure and in the right applications, increased well and equipment uptime without risk of costly integrity issues. This enables autonomous systems to be deployed in more remote areas, allowing the same level of assurance in control afforded to more infrastructure rich environments.
Collaborative Engineering Results in Application-Specific Hybrid Bit which Achieves Record Performance in Sichuan Basin
Authors: Zhang Lu , Valbuena Franklin , Zeng Jun , He Mingmin , Li Hongxing 
Published: November 2017

Abstract
China’s Sichuan Basin contains prolific gas fields and presents many drilling challenges due to the complex structural geology. Xujiahe is one of the most challenging formations in the basin. The interbedded and hard, abrasive nature of Xujiahe results in short intervals drilled and low rates of penetration (ROP).
Polycrystalline Diamond Compact (PDC) bits have limited drilling efficiency in this formation because impact damage and abrasive wear lead to short intervals drilled and very low ROP. Seven-bladed PDC bits which replaced roller cones were once believed to be the most cost-effective solution. To expedite gas exploration, improve ROP and increase distance drilled in the Gaoshiti-Moxi block, an innovative application-specific engineering drill bit was required.
To identify the solution, a cross-functional team from the drilling contractor and the service company conducted extensive technical research into drilling practices. Sophisticated software was used to analyze the rock properties, and to identify the formation drilling problems. Reviews of offset drill bits provided clues to drilling challenges. After a series of technical analyses, an application-specific hybrid bit was designed and tested in this block. Continuous optimization of drilling parameters is implemented by field engineer.
The first three trials drilled through this formation, saving two PDC bits and two trips over a 500-meter interval. Post-run review and analysis of the first trials was conducted for further improvement of ROP and interval drilling using drilling parameter and bottomhole assembly (BHA) optimization. One fast run with an average of 45% better ROP was achieved on following runs. This saved seven drilling days and 2.5 runs; an average savings of 180,000USD per well.
This paper describes the collaborative solution and detailed technical optimization of hybrid bit performance in Gaoshiti-Moxi Block. Based on the drilling data, economic analysis of this project is also presented. With this cross-functional team’s effort, how this success model may apply on other drilling projects will be also included.
A New History Matching Sensitivity Analysis Framework with Random Forests and Plackett-Burman Design
Authors: Aulia Akmal , Jeong Daein , Saaid Ismail Mohd , Shuker Muhannad Taleb , El-Khatib Noaman A. 
Published: November 2017

Abstract
To improve the current industry standard one-parameter-at-a-time sensitivity analysis method, we propose a new sensitivity analysis framework that utilizes Plackett-Burman design and Random Forests (a well-known data mining method). The new framework significantly reduces the number of required simulation runs (i.e. samples), and at the same time compellingly improves the automatic history matching error.
The proposed sensitivity analysis framework starts with generating samples/simulations using Plackett-Burman design. Here, each simulation is executed based on different combinations of the parameters' input values. Once the samples are ready, the parameters' input values and the target vector (i.e. the history matching error vector) are used to construct a Random Forests model. This model is used to rank the importance of each history matching parameter. Hence, parameters with low impact on the history matching error are discarded, and the remaining are used for Genetic Algorithm-based automatic history matching. The impact of an internal Random Forests parameter (number of decision trees) on the history matching error is also observed.
The highly faulted reservoir with water injection is used for history matching and 10 parameters are defined uncertain consisting of fault transmissibilities, permeabilities, and connate water saturation. The aim is to match the bottom hole pressure and watercut for several oil producing wells. The one-parameter-at-a-time method requires 21 samples, and the selected top 4 parameters from this method are mainly fault transmissibilities. The resulting automatic history matching results gave a final error of 463.338. With the new framework, which requires only 12 samples instead of 21, the final error was 628.041, given that 100 trees are utilized. As we increased the number of trees to 500, the final error is significantly better (i.e. 36% improvement) than the results obtained from the one-parameter-at-a-time method. We can see that using the new framework, the majority of the top 4 parameters are related to permeabilities. Here, there is no significant change in terms of computation time as we increase the number of trees from 100 to 500; total computation time is less than 10 seconds.
For this case study, not only this new framework requires significantly less number of initial simulation samples, it significantly improved the history matching error (as compared to the industry standard one-parameter-at-time sensitivity analysis method). Therefore, practicing engineers can utilize this framework to save time and simultaneously improve accuracy of the history matching parameter ranking. Parameter ranking computation with Random Forests takes less than 10 seconds.
Behind Casing Opportunity BCO of Poor Quality Reservoir - Unlocking a Mature Offshore Province
Authors: Hassani Hamed , Abdussalam Khomeini B , Majid Syahrani B , Zamzuri Mohd Dzulfahmi , Husain Nik Badrul 
Published: November 2017

Abstract
Behind casing opportunity (BCO) is an important production enhancement solution that extends field life in brown field development, specifically at low oil price and the current cost control environment. BCO potentially offers, low hanging fruit in terms of cost and realizing cheap oil, but successful maturation and realization of these opportunities relies on clear understanding of reservoir behavior and uncertainties. Historically, our ability to meet planned objectives has been challenging and in fact only 50% of these opportunities have met their objectives, the remainder compromised by either integrity or reservoir performance issues. An unconventional approach has been tested by the subsurface team and is presented here.
The approach presented here focuses on impact of workflow optimization, multidisciplinary and integrated work on instantaneous production gain. The sequential workflow includes data gathering, proper data preparation and integrating basic data and information (brilliant at the basics) to reduce inherent risk and uncertainty. A significant improvement in conventional petrophysical modelling, using proper analogs, unlock the potential resources which have been masked by low resistive elements. Detailed well modelling and performance analysis, highlights the potential gain from these low resistive pay zones. Coupled with a detailed screening process the opportunities with highest probability of success (POS) and most favorable commercial feasibility are selected.
The result demonstrate the huge upside potential for nominated low resistive pay zones that can be developed through BCO or horizontal infill target. On the commercial side, it was recommended to execute the plan in a campaign for cost optimization purposes. It is expected to reduce operational cost by 30 percent and improve recovery through realization of more drainage points. Progressive burning propellant stimulation has been initiated to maximize production gain by maximizing exposure to the reservoir and boosting flow capacity by a factor of two times through 25 feet of low perm section
Fracture Network Evaluation Using Tracer Flowback: A Case Study
Authors: Li Linkai , Pinprayong Verapich , Meng Fanle , Jiang Hanqiao , Li Junjian 
Published: November 2017

Abstract
Hydraulic fracturing is extensively applied in the exploitation of unconventional reservoirs. The evaluation for fracture networks after fracturing treatments has a great significance for hydrocarbon production prediction. In order to characterize fracture networks, the tracer is injected into the formation and it will flow back along with fracturing fluid. In this study, we estimate fracture networks using tracer flowback profiles (TFPs) based on temporal moment analysis.
Firstly, we conduct a correlation analysis between TFPs and microseismic (MS) event distribution for Xinjiang tight oil reservoir in China. And then, the relationship between cumulative flow capacity and cumulative storage capacity (F-C type curve) is developed using tracer flowback data by temporal moment method. The derivative of F-C type curve is applied to identify types of fracture networks. Finally, the results of fracture network evaluation obtained from tracer flowback are verified by the results from MS monitoring.
The correlation analysis indicates that fracture networks can be classified into three types: the first type of fracture network only comprised of several primary fractures, and TFP is multi-peak; the second type of fracture network comprised of primary fractures with some secondary fractures, and TFP is single-peak with a long tail; the third type of fracture network comprised of relatively uniform fractures, TFP is similarly of normal distribution. F-C derivative curve can be used to evaluate the types of fracture networks. If it does not have an abrupt change in F-C derivative curve, the fracture network can be considered as uniform distribution. If it has, the nearly horizontal line can be used to identify the number of primary fractures or fracture clusters.
Fracture network evaluation using tracer flowback is timely and of low-cost, which provides key information for reservoir-scale modeling and an alternative method for fracture evaluation. This study will definitely promote the management of tracer flowback.
Prohexadione‐Calcium Rate and Timing Effects on Alfalfa Interseeded into Silage Corn
Authors: Osterholz William R. , Renz Mark J. , Lauer Joseph G. , Grabber John H. 
Published: November 2017

Core Ideas
Higher prohexadione rates of 0.5 to 1 kg a.i. ha–1 enhanced interseeded alfalfa establishment and yield under stressful establishment conditions.Prohexadione application to 15 vs. 25 cm tall alfalfa seedlings provided similar improvements in alfalfa stand density and yield.Interseeding alfalfa increased overall corn+alfalfa forage production by 12%.
Prohexadione‐calcium (PHD) can enhance establishment of alfalfa (Medicago sativa L.) interseeded into silage corn (Zea mays L.), but optimal application rates and timing for this growth regulator are unknown. Two experiments examined how single or split applications of 0.25 to 1.0 kg a.i. ha−1 of PHD applied to 15 or 25 cm tall glyphosate‐resistant alfalfa seedlings influenced growth, stand density, and yield of alfalfa and corn compared to untreated controls. The PHD treatments reduced seedling top growth by 13 to 32% and increased stand density of alfalfa by 19 to 81% in three out of four locations and alfalfa dry matter yield by 4 to 23% in two out of four locations the following year. Alfalfa responses were not consistently influenced by the rate and timing of PHD application, but higher rates proved advantageous under conditions that impaired alfalfa seedling survival under corn. Application of PHD on alfalfa had little or no effect on corn heights and yields. Corn population and alfalfa seeding rates influenced corn silage yield and alfalfa stand counts in at least one location, but these factors had little effect on crop responses to PHD. Combined 2‐yr yields of corn followed by alfalfa were 12% greater for the interseeding system than for solo‐seeded corn followed by spring seeded alfalfa. Overall, a single application of 0.5 to 1.0 kg a.i. ha−1 of PHD on 15 to 25 cm tall alfalfa proved effective for improving stand density and occasionally first year yield of glyphosate‐resistant alfalfa.
Bioaugmentation with Nitrifying Granules in Low‐SRT Flocculent Activated Sludge at Low Temperature
Authors: Figdore Bryce A. , Winkler Mari‐Karoliina H. , Stensel H. David 
Published: November 2017

ABSTRACT: Nitrifying granules were grown in a sidestream reactor fed municipal anaerobic digestion centrate and added in an initial slug dose and subsequent smaller daily doses to a non‐nitrifying mainstream activated sludge system at 12 °C and 2.5‐day aerobic solids retention time (SRT) to increase its nitrification capacity. Effluent NH3‐N concentrations less than 1 mg/L were achieved with bioaugmentation, and nitrification was immediately lost when granules were removed after 30 days of bioaugmentation. Molecular microbial analyses indicated that nitrifying organisms remained attached to granules in the mainstream system with little loss to the flocculent sludge. Maximum specific nitrification activity of the bioaugmented granules decreased in mainstream treatment but the nitrification capacity remained due to new granule growth in the mainstream. This study demonstrated that bioaugmentation with sidestream nitrifying granules can intensify nitrification capacity in low‐SRT, low‐temperature flocculent activated sludge systems to achieve low effluent NH3‐N concentrations and nitrogen removal.
Household Recycling Behaviours and Attitudes toward Waste Bank Project: Mahasarakham Municipality
Authors: Singhirunnusorn Wichitra , Donlakorn Kidanun , Kaewhanin Warapon 
Published: November 2017

This study investigated factors influencing household recycling behaviour and the possibility of household participation in a community-based recycling bank project. The research examines two communities in Mahasarakham municipality, where there are differences in conditions and waste recycling management. The study demonstrated that demographic attributes and socio-economic factors play a little role in waste separation and recycling behaviour at household level. Meanwhile, environmental knowledge and attitudes contribute to the perceptions of people, their awareness, and participation to the community-based recycling project. Participation process was usually lacking in the project planning procedure and did not contribute enough time and resource to educate participants.
Efficacy and Long-Term Safety of C.E.R.A. Maintenance in Pediatric Hemodialysis Patients with Anemia of CKD
Authors: Fischbach Michel , Wühl Elke , Reigner Sylvie C. Meyer , Morgan Zoe , Schaefer Franz 
Published: November 2017

Background and objectives
The study was conducted to identify a conversion factor for switching from previous erythropoiesis-stimulating agents (ESAs) to continuous erythropoietin receptor activator–methoxy polyethylene glycol-epoetin beta (C.E.R.A.) and to document the efficacy and long-term safety of C.E.R.A. in pediatric patients with anemia of CKD undergoing hemodialysis.

Design, setting, participants, & measurements
In this open-label, multicenter study, patients aged 6–17 years, with stable chronic anemia of CKD, undergoing hemodialysis received C.E.R.A. every 4 weeks, at a starting dose determined by previous weekly epoetin alfa/beta or darbepoetin dosing. After a 16-week dose-titration and a 4-week evaluation period, patients with stable hemoglobin could enter a 1-year optional safety extension.

Results
A total of 64 patients were enrolled. A conversion factor (4 µg every 4 weeks for each weekly dose of 125 IU epoetin alfa/beta or 0.55 µg darbepoetin) was identified that allowed patients to maintain hemoglobin within target levels on switching to C.E.R.A. from another ESA. Using this conversion factor, the adjusted mean change in hemoglobin from baseline to evaluation was −0.09 g/dl (95% confidence interval, −0.45 to 0.26); 81% of patients maintained hemoglobin within 10.0–12.0 g/dl and 75% maintained hemoglobin within 1.0 g/dl of baseline. Results were consistent across age groups (6–11 and 12–17 years) and previous ESA. Thirty-seven patients entered the safety extension period and 17 completed 73 weeks of treatment. Most withdrawals were for kidney transplantation. A total of 70% of patients had hemoglobin within 10.0–12.0 g/dl at last observation, and 62% were within ±1.0 g/dl of baseline. Safety was similar to studies in adult patients, with no new signal detected.

Conclusions
Using a defined conversion factor, 4-weekly C.E.R.A. was efficacious in maintaining hemoglobin levels in pediatric patients with stable anemia of CKD undergoing hemodialysis, switching from maintenance treatment with epoetin alfa/beta or darbepoetin. Safety was consistent with the known C.E.R.A. safety profile in adults.
Potency of tea plant indigenous microbe on plant growth and to against blister blight disease (Exobasidium vexans Massee)
Authors: Fauziah Fani , Setiawati Mieke Rochimi , Susilowati Dwi Ningsih , Pranoto Eko , Rachmiati Yati 
Published: November 2017

The chemical control method of blister blight (Exobasidium vexans Massee) on tea could inflict various negative impacts. In order to obtain an environmentally sound control method of blister blight disease, a nursery trial has been conducted to know the effectiveness of bacterial combinations. The trial was carried out at Gambung experimental garden, with seven treatments and four replications. The indigenous microbial codes are Azoto II-1, Endo-5 and Endo-76. The treatments tested comprised: control (without bacteria),Â Azoto II-1 25% + Endo-5 75%; Azoto II-1 50% + Endo-5 50%; Azoto II-1 75% + Endo-5 25%;Â Azoto II-1 25% + Endo-76 75%; Azoto II-1 50% + Endo-76 50%; and Azoto II-1 75% + Endo-76 25%. All of the treatments was applied as a soil drench, 50 ml/plant with bacterial concentration at 0,5%. The parameter observed was blister blight disease intensity, plant heights, stem diameter, leaves number, root length, and root volume. The results showed that the combination of Azoto II-1 75% + Endo-5 25% could suppress the intensity of blister blight disease with disease intensity 1.27%. The treatments also affected plant heights, stem diameter, leaves number, root length, and root volume, 15.32 cm; 3.38 cm; 8.05 cm; 18.25 cm and 2.37 cm, respectively.