bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Study and Application of a Electric Intelligent Well Completion System with Electrically Driven Inflow Control Device and Long-Term Monitoring
Authors: Liao Chenglong , Zhang Weiping , Huang Peng , Zhang Guowen , Qian Jie , Shen Zejun , Pei Xiaohan 
Published: October 2017

Abstract
Intelligent well systems are useful in controlling multiple zones, managing water, reduceing well interventions, and increasing ultimate recovery especially for the high water cut well with multiple zones. The traditional hydraulic intelligent well systems are very complex, and high cost particularly in the current period of low oil prices. In this paper, we introduce a cable electric intelligent well completion system(EIWS), which is much convenient and low cost.
The system includes electrically driven inflow control devices(EDICD) connected to a ground control device through a single tubing-encased conductor cable, crossing packer, and remote controller. The EDICD consists of downhole valve, control circuit, temperature sensor, and pressure sensor, which can realize the inflow control and monitoring together. Multiple EDICD can be used to adjust production performance for multiple zones independently. The valve opening degree of each EDICD can be adjusted in no-step. The power supply and real-time signal transmission are achieved by the single conductor cable. The ground control device provides precision control of downhole valves and collection of monitoring data. The operators can remotely control and monitor the system from anywhere by the remote controller, which features an intuitive interface showing the valve opening degree and monitoring data.
The applications of the EIWS were carried out in Tuha oilfield for field trials. The EIWS was installed in conjunction with a rod pump during the workover of an existing completion. The maximum depth of well is more than 3000 meters. The results show that the EIWS is convenient and reliable. The production performance of the zone with high water cut can be effectively adjusted. Meanwhile, the change trends of temperature and pressure for each zone are easily observed.
The long-term monitoring and real-time control are useful for the optimization of well production performance with higher efficiency. Moreover, the reduction of well interventions can save cost. This paper will illustrate the key learnings based on the field trials.
Modelling Trapped Gas Expansion in Water-Drive Reservoirs
Authors: Babadimas J. M. 
Published: October 2017

Abstract
Imbibition only relative permeability is commonly used to model water influx in water-drive gas reservoirs, however an aquifer is rarely strong enough to maintain constant pressure support. Continued pressure depletion in the part of the reservoir swept with watercauses expansion and remobilisation of trapped gas behind the waterfront. This paper presents a reservoir simulation study on modelling the expansion and remobilisation of trapped gas due to pressure depletion as secondary drainage flow using relative permeability hysteresis.
Previous studies in literature on relative permeability show the secondary drainage curve during blowdown is below the primary imbibition curve. This is based on field cases and core experimental studies, which establish the existence of a gas remobilisation threshold above residual saturation to reconnect the gas phase. Commonly used hysteresis models by Killough (1976) and Carlson (1981) are unable to model secondary drainage flow below the primary imbibition curve. The ODD3P hysteresis model developed by Hustad et al. (2010) was identified as the most appropriate method to model trapped gas expansion as secondary drainage flow below the imbibition curve. A reservoir simulation study was performed using the ODD3P hysteresis model to test scenarios which model trapped gas remobilisation as secondary drainage flow during pressure blowdown after waterflooding.
The conclusion of this study is that the standard formalisms used to model relative permeability hysteresis (Killough, Carlson) should not be used to model trapped gas remobilisation due to blowdown as they do not incorporate a gas remobilisation threshold and a secondary drainage curve underlying the primary imbibition curve. By assuming no mobility threshold above residual gas saturation, the total recovery of residual gas will be overestimated. Instead, by adopting the ODD3P hysteresis model, gas production will be lower and water production higher due to the correct use of secondary-drainage relative permeability curves in a gas reservoir invaded by water. This will lead to a significant improvement in results from reservoir simulation and the subsequentevaluation of trapped gas recovery.
The expansion and remobilisation of residual or trapped gas saturations has a major impact on the prediction and/or matching of production and pressure response from a reservoir. This study intends to understand these impacts and serve as a preliminary guideline in modelling trapped gas expansion and remobilisation as secondary drainage flow, which is applicable to many water-drive gas reservoirs.
Multiple Stage Vane Pump, a New Production Technology Used in Thermal Recovery Well
Authors: Quanbin Wang , Lixin Zhang , Shijia Zhu , Hongmei Huang , Tong Guo , Yongxin Li 
Published: October 2017

Abstract
China has a large quantity of heavy oil reservoir and many steam flooding wells and steam soaking wells. At present, normal artificial lift forms cannot meet the requirements for both high temperature lift and efficient lift. The traditional vane pump is a positive displacement pump which features its good high-temperature resistant performance and stable flow characteristics. Based on these features, the new multiple-stage vane pump (MVP) was designed. In the MVP, the flow direction was changed to the axial direction for fitting the slim wellbore; two or three stages were assembled in series connection for increasing the pumping pressure. In the laboratory, the comprehensive experiment workbench was used to test the relationship between pumping pressure, flow rate and other hydraulic parameters. The results show that MVP has smaller operation torque, high volumetric efficiency and high system efficiency. The artificial lift system of MVP uses conventional drive head as the energy source and sucker rod to transfer the energy downwards. The transmission system is specially designed for the MVP system, which can be used for power transmission, sand control and steam injection. It can realize the functions for both production and steam injection, which means that the production tubing and MVP are not pulled out in steam injection periods. The vane pump had been deployed in eight wells, two of them with steam injection valve. Compared with the beam pumping unit with the similar liquid-producing capacity, the energy consumption for the vane pump is about 30 percent lower.
Coalbed Methane Development in China: Engineering Challenges and Opportunities
Authors: Li Hangyu , Lau Hon Chung , Huang Shan 
Published: October 2017

Abstract
Commercial development of coalbed methane (CBM) in China has lasted for a decade. However, in 2015 annual CBM production in China was less than 5 Bcm and lagged far behind those in US (35 Bcm) and Australia (18 Bcm). In this paper, we review the published literature to determine the engineering challenges and opportunities of CBM production in China. Our review has identified seven major engineering challenges to CBM development in China. They are low cleat permeability and underpressured formation pressure of high-rank coals, ductility of coal seams, suboptimal fracturing fluids, formation damage during drilling, borehole instability in horizontal wells, frequent pump failures during production, and inadequate produced water treatment methods.
Each of these challenges provides an opportunity for improvement. We propose a refocus on low-rank coals which have higher permeability. Other opportunities include development of better hydraulic fracturing fluids, non-formation damaging drilling fluids, use of geomechanics to understand borehole instability, optimization of the artificial lift methods and more robust and environmentally friendly produced water treatment methods.
Study on Non-Contact Connection Separated Layer Production Technology and Its Application Test
Authors: Tong Guo , Xiaohan Pei , Yafeng Ju , Fuwei Bi , Quansheng Zhang , Qinghai Yang 
Published: October 2017

Abstract
Separated layer production is an effective means to mitigate inter-layer problems, minimize invalid water circulation and improve oilfield production efficiency. A non-contact connection separated layer production technology is developed in this paper to realize the automatic monitoring and control of production wells.
By developing a downhole production parameter monitoring and CPU management system, acquisition of downhole pressure, flow and temperature data, control of flow control valve opening, and saving of historical test and adjustment data into downhole system can be realized. A downhole communication sub is used for signal transfer. The ground and downhole communication sub communicate with each other via power line carrier, while the downhole communication sub makes wireless communication with the downhole automatic control system. Downhole charging from the ground is realized by utilizing the non-contract charging type power supply system.
An oil well test study is carried out based on this technology. The maximum temperature of the test well is 82°C, and the water cut is 96.8%. With successful downhole non-contact connection, stable and reliable data transmission at a rate of 9,600bps, and no data packet loss during communication, the test results have verified the feasibility of this technology and the realization of automatic monitoring and control of downhole working conditions. The downhole charging current is 7.4A, and the electric energy conversion efficiency is 31.4%. According to calculation results, the battery can be used for more than 20 times of automatic allocation of production flow. The adjustment interval is set at one month and the system can work continuously for more than one and a half years under this condition.
In this paper, the technical problems of non-contract charging and wireless data transmission in high temperature downhole environment are solved successfully, and a downhole separated layer production automatic control system is developed.
Novel Single-Trip Well Re-Stimulation Technology Enables Exact Treatment Placement While Significantly Decreasing Intervention Time
Authors: Castro Luis , Nasir Ehsaan , Wilbourn Maurice 
Published: October 2017

Abstract
This paper focuses on an operational review and lessons learned during the deployment of a novel straddle packer system in a refracturing application. The operation involved the deployment of an industry-first high-rate / high-pressure straddle packer to convey a propped refrac job to a previously producing well in a challenging application. The paper will also include relevant notes on operational time optimization derived from the field implementation as well as pre and post-treatment production information.
The paper describes details on overcoming the challenge of effectively isolating a single group of perforations among multiple producing zones of a wellbore in order to deliver a targeted stimulation treatment. The paper also discusses opportunities for improvement and learnings from this novel deployment. Finally the paper analyzes pressure and temperature data gathered during the treatment to assist in understanding job execution as well as post-treatment production information.
The novel stimulation technology enabled the operator to accurately place a propped refrac treatment at 20 bpm in a 200ft-long interval of previously producing perforations in a single run. The application reduced the operational time on location by 30% and reduced the number of runs required to complete the operation. Comparative production results will be shown as a measure of treatment effectiveness.
The paper contributes a novel insight to the intervention, stimulation, and refracturing industries by describing one of the first successful high-rate re-stimulation jobs using a straddle packer with open perforations above and below in a single trip. This insight is relevant as it highlights a cost-effective alternative for reviving existing wells at a fraction of the cost of a new drill, without the need to deploy numerous tools and fluids in multiple trips to achieve the zonal isolation as typically required in a re-stimulation treatment.
Application of Controlled-Influx Mud Cap Drilling Techniques in Exploiting the Marine Pre-Salt Carbonates in Santos Basin: Case Study
Authors: Yaqoob Tanveer , Bello Opeyemi , Oppelt Joachim 
Published: October 2017

Abstract
The pre-salt Coquina Carbonate beds in the Santos Basin are the prime focus of major oil producers in the region. In addition to the thick, unstable salt layers posing borehole stability and casing issues, a primary challenge in the appraisal of the faulted Coquina reserves is the handling of immense downhole losses in the weaker and occasionally fractured carbonate layers just below the salt strata. Although the bottomhole pressure limitations posed by conventional drilling have been eliminated by Managed Pressure Drilling attempts, the transition has also brought along a new set of technical challenges such as: Instability in wells while tripping and high fluid losses while restoring controlFailed attempts to regain control in loss zones by pumping lost circulation material/cement into fracturesDifficulty in zonal isolation, even with Managed Pressure CementingPore plugging and reservoir damage due to placement of cement as lost circulation materialWellbore depletion and differential sticking tendency during shut-in timeLimitations on the use of Positive Displacement Motors due to additional pressure fluctuations
The paper reviews the above challenges as planning and technological gaps suppressing the production prospects and investigates the application of Pressurized Mud Cap Drilling and Constant Bottomhole Pressure techniques with controlled Gas-Influx as an effective approach in mitigating the constraints by aligning the bottomhole pressure and the pore pressure. A case study for immense downhole losses in the reservoir interval has been presented. The results of feasibility analysis on reported case histories depict that circulating out the influxes while drilling with improved Surface Back Pressure systems minimizes losses, improves completion quality and reduces shut-in gaps.
Multiple Sand Control Solution to Adapt Well Productivity and Reserves by Using Mahakam Sand Control Tool Box
Authors: Styward B. , Muryanto B. , Wahyudhi F. , Wijaya R. 
Published: October 2017

Abstract
Multizone Single Trip Gravel Pack (MZ-STGP) Completion has been utilized as primary sand control system in Total E&P Indonesie. Over 250 wells have been successfully delivered since 2005 to maintain production plateau. Currently, the main challenge of this system is how to tackle number of marginal wells with higher geological uncertainties.
In order to ensure well economy, several completion systems need to be prepared as an alternative of the MZ-STGP in order to adapt with the actual well reserve. In fact, the alternative systems should have flexibility to replace MZ-STGP in a very short time to avoid rig standby. This paper will review the alternative solutions which provide both capability and flexibility to replace MZ-STGP in a very short time in order to unlock marginal reservoirs.
Thorough engineering design and progressive trial were performed since 2008 with the involvement of drilling contractors and transverse entities. The main objective of the trial is to implement the alternative system safely without hinder production performance and keep maintaining overall cost as minimum as possible. Mahakam Sand Control Tool Box (M-STOB) was then developed as group of alternative solutions to tackle the challenges mentioned above. It consists of four main solutions; Modular Gravel Pack System, Openhole Solution, Slim Gravel Pack and Thru Tubing Sand Control. Through these solutions, company is expected to have flexibility to adapt well architecture in a very short time based on actual well reserve.
Integrated 3D Pore Pressure Characterisation and Modeling: Methodology & Application in Sisi Nubi Field, Mahakam - Indonesia
Authors: Sukapradja Aldyth , Herdianto Roni , Clark Jesse , Adam Cepi , Ashari Untung , Saragih Baginda , Sitorus Rio , Giriansyah Bayu 
Published: October 2017

Abstract
Sisi-Nubi (SNB) is a gas field located 25 km offshore from the modern Mahakam delta with overpressure reservoirs being found typically in the Sisi Main Zone (SMZ) interval. SNB 3D seismic data indicates a velocity reversal in the SMZ interval, where the overpressure occurs. This velocity reversal has a relation with location of shelf break (distal area), where beyond shelf break the NTG value is sharply decreased.
In the Mahakam area, overpressure gas reservoirs are one of the main issues in terms of drilling hazards. This has been historically managed by integrating surrounding wells' pressure data to predict the pore pressure profile that would be expected in an upcoming well. In new areas or where pressure data is lacking, it is difficult to predict the PP which can result either in heavier than necessary well architectures or an increased risk of taking a kick.
An integrated pore pressure study has been carried out on the SNB field in order to provide three dimensional and spatially continuous pore pressure prediction using four different disciplines: sedimentology, reservoir geology, geophysics and geomechanics. The integrated pore pressure model over SNB is contained within a 3D geological model where the Eaton equation can be run using following datasets: sonic well data and sedimentological trend (Well Driven model), upscaled/resampled seismic interval velocity (seismic driven model) and hybrid method as compromise between two data sources involves using the seismic data as a soft trend for the extrapolated well data (hybrid model).
Based on the blind well test analysis, the hybrid methodology shows the best result in terms of precision and 3D distribution and allows a continuous prediction of pore pressures even where there is poor well control. However, the others two methodologies could be used as an alternative when the available data is limited.
This methodology gives a new approach with more integrated information in 3D pore pressure modeling that improved the classic pore pressure prediction in field Scale and/or basin scale. However, with the remaining uncertainty and discrepancy between the DT well scale velocity and the DT seismic velocity, and considering all detail well events important inputs (Gas evolution including long connection tests, kick, pressure test, HC bouyancy and other drilling events), collaboration with a strong 1D Pore Pressure synthesis will give a comprehensive result.
Pushing Boundaries through Simplification of Complex Carbonate Reservoir Modeling: Small Investment, Big Gains
Authors: Khor Y. Y. , Shrivastava S. K. , Borhan N. A. , Baghdadi F. , Motaei E. , Kadir Z. , Supaat S. F. , Anasir N. , Mithani A. H. 
Published: October 2017

Abstract
Material balance analysis, a primary engineering technique, is an indispensable tool used for understanding the production performance and field management of mature gas reservoirs. Compilation and analysis of pressure-production data together with acomprehensive geological understanding including in-place hydrocarbon volumes and inter-block communication are prerequisites for material balance analysis. Deviation of observed P/Z data away from a straight idealised line necessitates further study, as it often indicates erroneous estimates of participating in-place volumes, aquifer support or reserves. Lack of pressure measurements, questionable stratigraphic correlations and uncertainty surrounding aquifer propertiesor reservoir connectivity highlight the requirement for further evaluation.
The objective of study is to develop a multi-tank material balance modelfor a mature, heterogeneous and compartmentalised carbonate gas field. Ultimately, the model must besufficiently robust to elucidate the field's production mechanism and optimise future field-development opportunities.
In this field, the pressure production behavior can be divided into two trends, an early rapid declining pressure trend, followed by a stabilised gradual pressure decline. Owing to higher drawdown in the field's early production life and insufficient recharging, the quick pressure decline underestimates the initial in-place gas volume. This volume is not adequate to support the sustained gas production rates observed in later years. This observation required further detailed analysis regarding the nature of zonal communication across adjacent reservoir intervals to better understand the production behavior of development wells during the design of the material balance model.
This paper discusses a study in which material balance analysis is coupled with multi-field network models. Implementation of this workflow can be usedto drive subsurface developmentsin a relatively short period.
A Dynamic Hybrid Dual Porosity Model to Simulate the Waterflood-Induced Fractures in Low-Permeability Reservoir
Authors: Tianyi Fan , Shuhong Wu , Hua Li , Baohua Wang , Xiaobo Li 
Published: October 2017

Abstract
A new type of fracture which was caused by the waterflooding process in the low-permeability reservoirs has attracted the engineers’ great attention in China recently. This new type of fracture, named the waterflood-induced dynamic fracture, has a significant impact on the swept volume of water flooding and the distribution of remaining oil, and therefore, directly affects the reservoirs development. However, because of the special features of these fractures, such as the morphological changes, the time-varying permeability and vulnerable to the production performance, it is almost impossible to characterize them accurately in the normal reservoir simulation.
In order to describe the waterflood-induced dynamic fracture, a new model was established in this paper. By overlapping the dynamic fracture model and the psudo-tenser permeability model to the dual porosity model which consists of a set of disconnected matrix blocks and a network of connected fractures, a new dynamic hybrid dual porosity model was derived. Compared with the conventional dual porosity model, the dynamic hybrid dual porosity model allows the property of the fracture system to change with time, so that the above problems can be solved very well.
Through the numerical simulation of a typical low-permeability oilfield by using the established model, the evolution process of the waterflood-induced dynamic fracture including opening, extending and closing, and its impact on the development of the low-permeability reservoir were carefully studied. The simulation results show that the dynamic fracture grows continuously and slowly throughout the entire life of the oilfield development. And it has significantly narrowed the water flooding swept range, and reduced the vertical producing degree of water flooding to a certain extent, which is very consistent with the production performance data of this oilfield. Meanwhile, the precision accuracy of simulation result has been observably improved by using this new model, which indicates that the model can precisely depict the changes of the dynamic fracture both in its morphology and its properties.
Furthermore, the established dynamic hybrid dual porosity model could be used to elucidate the mechanism of the evolution of the waterflood-induced dynamic fracture and so forth. Therefore, it provides an important technical means for the study of the effective development and prompt adjustment of water injection policy of low-permeability reservoirs.