bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating Gas–Adsorption, Stress–Dependence, and Non–Darcy–Flow Effects on Gas Storage and Transfer in Nanopores by Use of Simplified Local Density Model
Authors: Pang Yu , Soliman Mohamed Y. , Sheng Jie 
Published: November 2017

Summary
As an unconventional rock, shale contains all the features of coalbed and tight sandstone specified as gas-adsorption capacity, microscale and nanoscale porosity, and extremely low permeability. The gas-storage mechanism of shale rocks not only is dominated by free gas in macropores and natural fractures, but also is controlled by adsorbed gas in microporous organic matter (kerogen) and clay minerals. Furthermore, Darcy's law is no longer applicable to describe gas transport in nanopores (Javadpour 2009; Wu et al. 2015). Therefore, developing a reliable model to calculate effective porosity and permeability in nanopores considering the effects of gas adsorption, stress dependence, and non-Darcy flow is crucial to characterize properties of shale-gas reservoirs and explain gas-flow behavior in nanopores.
In this study, the simplified local density (SLD) model, which has been successfully applied to analyze gas adsorption on coal, activated carbon, and shale in recent studies, is used to analyze methane-adsorption data measured from five shale-core plugs in the laboratory (Mohammad et al. 2011; Chareonsuppanimit et al. 2012; Clarkson and Haghshenas 2016). A new approach to determine the thickness of adsorbed gas dependent on the density profile of the SLD model is proposed, which in turn provides the correction of methane adsorption to pore volume (PV). Furthermore, stress-dependence effect is incorporated into the gas-adsorption effect to generate an effective porosity function in shale rocks. In addition, non-Darcy-flow effect on gas transfer in nanopores is derived from the slit-shaped pore geometry of the SLD model and is represented by a weighted sum of second-order gas slippage and Knudsen diffusion. Consequently, the effective permeability is established as a function of the effects of gas adsorption, stress dependence, and non-Darcy flow. Moreover, the functions of effective porosity and permeability are incorporated into a numerical simulator to perform history matching for gas-production data from a horizontal well with multistage hydraulic fractures in a Barnett Shale reservoir. The simulation results properly match the gas-production data at the field scale. Finally, sensitivity studies on gas adsorption, stress dependence, and non-Darcy-flow effects are conducted to investigate their contributions to evaluating and estimating gas production from shale-gas reservoirs.
The results of this study suggest that gas adsorption and non-Darcy-flow effects are two competitive aspects that have major influences on shale-gas production. The developed model including gas-adsorption, stress-dependence, and non-Darcy-flow effects provides insight into the characterization of rock properties and the description of gas-transport behavior in shale-gas reservoirs.
Rigless Deployment of Innovative Electrical Submersible Pumping System for First Time Worldwide
Authors: Winarno Mulad B. , Said Rifat , Shawly Alaa S. , Mutairi Khaled M. , Rafie Majid M. , Roth Brian A. , Sarawaq Yahya 
Published: November 2017

Abstract
Electric Submersible Pumps (ESPs) is very popular artificial lift systems to boost oil production now days. Home ofmany ESP installations, with high frequency of change outs per year and with the harsh production environment, a development of ESP technologies to reduce change-out time and improve run life is keep ongoing. These technologies address business challenges timely in a proactive approach. Currently deployed ESPs require a time-consuming rig installation on jointed tubing. With several factors such as: an average run life of three years for ESPs, a rig-based change-out time of up to two weeks offshore, and an uncertainty of when a rig can be scheduled; the need for a more rapid rigless solution is critical for future operations.
Majority of the ESP installation are completed as part of tubing completion and deployed by drilling rig which requires high spending to recover the well during ESP replacement. Several types of technologies to deploy ESP rig-lessly were introduced into industry to optimize the retrieval and deployment cost during ESP replacement. Limited success story was recorded and open more thought to overcome the challenges.
The first worldwide new reliable cable rigless deployed electrical submersible pumping (ESP) system was successfully installed and put on production. What makes this system unique concept and the first worldwide of its kind are two main components. The first component is the innovative cable hanger design that insures total cable isolation while providing a non-restricted flow through the tubes that are built into the body of the spool. The second component is the specially designed and manufactured CT from selected material that has high resistance to H2S and CO2 and it was made exactly fit the ESP cable providing full protection from corrosive wellbore fluid. This design aimed to boost production of oil wells with lower ESPs installation and replacement cost. The new system eliminates the need for and expensive rig to replace the ESP and accelerate production restoration. This system will be a great addition especially for offshore environments where not only the rig intervention costs are expensive, but also limited rig availability can delay ESP replacement.
This paper will share the concept, design, field implementation planning and technical challenges, lesson learnt during preparation and installation of this first of kind system.
Microseismic Monitoring: A Tool for Evaluating Fracture Complexity in Various Geological Settings
Authors: Calvez J. Le , Hanson-Hedgecock S. , Fredd C. N 
Published: November 2017

Abstract
Understanding the created fracture geometry is key to the effectiveness of any stimulation program, as fracture surface area directly impacts production performance. Microseismic monitoring of hydraulic stimulations can provide in real-time extensive diagnostic information on fracture development and geometry. Thus, it can help with the immediate needs of optimizing the stimulation program for production performance and long-term concerns associated to field development. However, microseismic monitoring is often underutilized at the expense of productivity in the exploration and appraisal phases of a field.
Geology is a fundamental element in the design of a stimulation program and the interpretation of its results. Rock properties and geomechanics govern the achievable fracture geometry and influence the type of fluids to be injected in the formation and the pumping schedule. Rock layering controls the location of the monitoring device, guides the depth at which perforations should be located, and influences how hydrocarbons flow within the formation. Despite this importance, the impact geology may have on the stimulation results is often overlooked as it is all too common to see assumed laterally homogeneous formations, invariant stress field (both laterally and vertically), stimulated fractures having a symmetric planar geometry, etc.
As exploration and appraisal moves toward active tectonics areas (as opposed to relatively quiet passive margins and depositional basins), understanding the impact of complex geology and the stress field on fracture geometry is critical to optimizing stimulation treatments and establishing robust field development plans. Mapping of hypocenters detected using microseismic monitoring is an ideal tool to help understand near- and far-field fracture geometry. Additionally, moment tensor inversion performed on mapped hypocenters can contribute to understanding the rock failure mechanisms and help with evaluating asymmetric and complex fracture geometry. Understanding this fracture complexity helps address key uncertainties such as achievable fracture coverage of the reservoir.
We present the results of several hydraulic fracture stimulations in various geological environments that have been monitored using microseismic data. We illustrate with these case studies that in some rare cases, simple radial and planar fracture system (often mislabeled penny shape-like fracture) may be generated as predicted using simple modeling techniques. However, in most cases, the final fracture system geometry is complex and asymmetric, largely governed by stress, geologic discontinuities, rock fabric, etc. Understanding this impact and optimizing the well design to enhance productivity is key to evaluating reservoir potential and commercial viability during exploration and appraisal phases and for maximizing return on investment during development.
Green EOR Utilizing Well-Defined Nano-Cellulose Based Nano-Fluids from Flask to Field
Authors: Wei Bing , Li Qinzhi , Li Hao , Lu Laiming , Pu Wanfen 
Published: November 2017

Abstract
The environmental issues of the traditional oilfield chemistries are challenging the Enhanced Oil Recovery (EOR) industry. Therefore, eco-friendly chemical EOR methods must be quickly developed. In this work, an abundant natural polymer on earth, nano-cellulose, was extracted from the plant-based materials and then introduced to EOR. On the basis of the original nano-cellulose, a series of surface-grafting were performed for the interest to make it more favorable for EOR application, thus generating the well-defined nano-cellulose based nano-fluids. The EOR related properties including morphology, thermal stability, rheology, etc., were first studied. The displacement responses of the nano-fluids were then collected. Thereafter, these nano-fluids were introduced to foam EOR as foam film stabilizers. The results showed that the nano-fluids exhibited superior thermal resistance, salt tolerance and viscoelastic properties after surface-grafting. As a result of the amphiphilic nature, the stabilities of surfactant foam in the absence and presence of crude oil were significantly improved by using the tested nano-fluids and 12% of incremental oil recovery was obtained in this stabilized foam flooding. When this nano-fluid was used alone to displace the oil in place, 6% of incremental oil recovery was produced after 0.4 PV nano-fluid slug was injected. The experimental findings obtained from this work promised the nano-cellulose based nano-fluids as green agents in chemical EOR.
Advances in Rigless Well Abandonment: Pathfinder to Enormous Economic Advantage
Authors: Singh Alok , Prakash Aditya , Kothiyal Manish , Sarma PJ , Srivastava Rajendra 
Published: November 2017

Abstract
The inevitable depletion of oil and gas reservoirs beyond economic viability requires Permanent Well Abandonment (PWA) as per the applicable regulations to isolate in perpetuity all freshwater and hydrocarbon (HC) bearing zones encountered in the well. It is an operation where significant investment is made with no financial return. Therefore, it is prudent to limit the economic impact while fulfilling abandonment objectives through improved tools and techniques such as rigless PWA.
While conducting abandonment utilizing a Rig is a standard practice, rigless PWA procedure is a non-routine operation with huge economic advantages. Its suitability must be assessed (defined by the regional practice/standard) and technical suitability (governed by well specific details).
This paper presents a review of global best practices and standards for rigless PWA and its comparison to the standards applicable to India. A case history of conducting PWA of a standalone onshore gas producer well is then presented. A review of the well details was conducted to as certain the well's suitability for rigless PWA. A detailed procedure and risk register was developed to evaluate candidates.
A rigless PWA spread primarily utilizes cementing, E-lineand and Slickline units. An innovative approach aimed at limiting the economic impact was adopted. The requirement for E-line was eliminatedby using Digital Slickline which combines the capabilities of Slickline and E-line. Rigless PWA was successfully executed on the well ‘X’, resulting in savings of about $1.5 mmas compared to rig based PWA. Utilizing DSL saved approximately ~ $200k over the rigless work with E-line.
The application of this rigless technique to the rest of the organization's aging wells, both onshore and offshore, has the potential for massive savings. In the shorter term, the application of rigless PWA of wellbore prior to side-track operations is being planned for upcoming offshore drilling campaigns. This should save ~ 0.5 mm USD/well ascompared tothe conventional approach of rig based PWA of the original wellbores.
High Alloyed Duplex Stainless Steel for Reliable Seawater Cooling
Authors: Höwing J. , Ghai B. 
Published: November 2017

Abstract
The hyper duplex grade UNS S32707 has, together with other duplex stainless steel grades, been tested in a model heat exchanger with chlorinated seawater on the tube side. The test periods have been 6 to 18 months with a maximum outer skin temperature of 170°C, giving an inner skin temperature of 95°C. The test results show that standard duplex of type 2205 andsuper duplex stainless steel of type 2507 develop pitting corrosion at an inner skin temperatures of 50°C and 70°C, respectively. The hyper duplex alloy S32707 does not show corrosion under any of the tested conditions. This shows that hyper duplex S32707 is a viable stainless steel option for demanding seawater cooler applications, being able to replace expensive nickel base alloys and titanium solutions.
Development and Application of a Modified Superheated Steam Flooding Assisted by N2 Foam and High-Temperature Resistant Gel
Authors: Anzhu Aut Xu , Longxin Mu , bing Bo , fachao Shan , Xingbo Li 
Published: November 2017

Abstract
Superheated steam has a smaller density and a larger specific volume than conventional saturated steam, and has a stronger override effect in heavy oil reservoir. As most of heavy oil reservoirs have strong heterogeneity because of high porosity and permeability. Therefore, the steam injection profiles vary greatly and vertical producing degree of reservoirs is very low. Nitrogen with a large compression coefficient, large volume coefficient, large expansion volume capacity, can feed the formation energy and acceleratively drive heavy oil efficiently. For another, the surfactant in the foam can reduce the oil-water mobility ratio. High temperature-resistant gel can seal steam breakthrough channel due to its high permeability. Nitrogen foam and gel flooding can increase the superheated steam swept volume, improve the effect of superheated steam flooding in heavy oil thermal recovery. The injection parameters of nitrogen foam and high-temperature resistant gel were systematically studied by numerical simulation combined with physical simulation method in this paper. Gel, foaming agent, nitrogen injection sequence and injection method determined the improvement degree of steam injection profile modification. The results showed that under the injection rate of foaming agent was 240m3/d, the daily injection of nitrogen was 2000m3/d, the total injection amount of foaming agent was 16,000m3 in early slug injection, the effect of thermal recovery was the best. Application of this technology in KMK heavy oil field can enhance heat insulation effect of wellbore, decreased thermal lost by 15.5%, modified superheated steam injection profile by 36.3%, increased vertical producing degree of the reservoirs to 65.8%, feed formation energy in high efficiency. The superheated steam injection profile modification method by N2 foam and gel shows great economic prospect as a way of plugging steam breakthrough channel, controlling steam override and enhancing heavy oil recovery.
Combined Investigation of Effects of Contact Stresses, Pore Size and Rotary Dynamics on Mud Plastering in Prevention of Lost Circulation in Weak Zones during Casing Drilling
Authors: Meza Oscar Grijalva , Yaqoob Tanveer , Bello Opeyemi , Boulakhrif Faissal , Holzmann Javier 
Published: November 2017

Abstract
While drilling with casing stands instead of the classic drill pipe (CwD), the reduced standoff between wellbore wall and the rotating, sliding and bending tubular plays a critical role by "crushing and hammering" the formation cuttings into the formation. This plastering effect has demonstrated to be not only beneficial to hinder the losses of drilling mud into the formation but also to improve wellbore stability and later productivity in terms of lower skin values.
Field trials have established that monitoring of cutting sizes accumulated on the shakers and their correlation to the formation pore sizes (through offset match or well tests) can be an effective approach to improvise on the mud particle size for effective particle bridging and formation sealing. To enhance the mitigation of CwD-induced losses and formation damage, however, the horizon of investigation has to be broadened to include the size of radial clearance, rotating speed (RPM) and pump hydraulics. Assuming the cutting and mud smearing to be the result of point contact forces altering the near-wellbore stresses (confining stresses), the above parameters cause a repeated but unsynchronized invasion of particles in the initial micro fractures created due to bit interaction. Depending on the RPM, radial clearance and the resulting induced lateral drillstring movement, the magnitude of the contact force / hoop stresses increases within the original fracture-gradient limits. This improves formation sealability and results in an altered (enhanced) pore- and fracture gradient in the near-wellbore region.
The paper discusses the effect of Geo-mechanical and mechanical aspects of Plastering during Casing Drilling in Weak or depleted wellbores. The experimental analyses incorporates the combined effect of the point contact-forces through base drilling parameters, alongside highlighting the approach for field mud particle-size improvisation. Altogether, a broader panorama concerning the contribution of Casing Drilling to Well Integrity has been presented, setting the path to further experimental work.
Study on a MEMS-Based Piezoelectric Energy Harvester
Authors: Tao FU , Xiaohan Pei , Qinghai Yang , Yili Hu , Eryang Ming , Siwei Meng , Shouzhi Huang 
Published: November 2017

Abstract
At present, most of the small-scale equipments used in monitoring underground oil exploration pipelines are powered by disposable or rechargeable batteries. These traditional chemical batteries have been unable to meet the needs of the system due to their large mass and volume, limited energy supply and possible environmental pollution. In addition, the huge depth of the oil wells can lead to a great deal of inconvenience during the replacement of the batteries. To solve these problems, a piezoelectric vibrator based on MEMS is proposed to achieve continuous supply of small downhole equipment in the process of oil/gas development.
In this study, after analyzing and optimizing the structural parameters of the device, a prototype is designed and fabricated through MEMS processing techniques including bulk silicon micro fabrication, bonding, and thinning. The prototype consists of a support layer, a piezoelectric film layer and a tip mass-block. Copper or silicon with appropriate stiffness and suitable for MEMS processing techniques are selected to make the support layer; PMN-PT with superior performance is selected to fabricate the piezoelectric film layer, whose working mode is d31. By running the energy acquisition test, the characteristics of the prototype's output voltage, power, and frequency are studied, as well as the possible requirements for the matching circuit.
The study shows that the test results are in good agreement with the calculated results of the theoretical model. The test results show that when the acceleration is 1.5g, the frequency bandwidth of the proposed prototype is 34.6Hz in air and 50.3Hz in silicon oil, and the output power can reach 35.4μW in air and 4.96μW in silicon oil.
Compared with the current mainstream piezoelectric thin film MEMS devices, this energy harvester based on MEMS technology has the advantages of superior output performance, simple fabrication, high anti-electromagnetic interference reliability, and easy integration with support circuit. This device will provide a new solution for the energy supply of downhole small-scale monitoring equipment.
Drains - A Hidden Source of Explosion!
Authors: Molelputhenpura Kuriakose Mathew , Adel Khalid , Al Awadhi Ibrahim 
Published: November 2017

Abstract
Proper functioning of the drainage system in oil and gas plant is vital for uninterrupted operation of the plant facilities. Among the various drainages, oily water drainage system is critical with high risk considering its hydro carbon content and accumulation of explosive vapours due to improper functioning of any components in the system. This paper presents some of the shortcomings in the design/arrangement/maintenance of the different elements and the improvements to avoid accidents.
The drainage types in GASCO plants are Clean Water Sewer, Sanitary Sewer, Oily Water Sewer (Accidentally Oil Contaminated / Continuously Oil Contaminated) and Chemical Drains. One of the unforeseen risks has caused an explosion in an existing oily water sump inside the process area. The sump was of concrete construction and the cover slab was blown up resulting in considerable damages to the surrounding pipes/support. There was no injuries to personal. The root cause analysis of the incident was done and a study carried out for a safety review of oily water drainage system at all plants.
A study was carried out to identify possible hazards/design deficiencies of the oily water drainage facilities and recommend measures for rectification and risk mitigation. The study identified that the lines are placed in slope & mainly "run dry" after use, liquid seal not available in some manholes causing HC vapour upstream movement, the manholes/sumps are closed, vent pipes size is small and some are blocked. These lead to accumulation/formation of hydrocarbon mixture inside closed sump, ignition by overheating of the pump installed over the pit and subsequent explosion. Recommendations for existing system include regular flushing of the lines with water to ensure transport of oily effluent & maintain liquid seal, regular removal of the floating hydrocarbon liquid from pits using vacuum truck, open up the manholes and use grating covers, provide self-skimming bucket where feasible, etc. Additionally, for new facilities it is recommended to lay the pipes horizontally to ensure liquid seal, provide turn-up elbows to reduce hydrocarbons accumulation in manholes, provide oil skimming/baffle wall in oil/water sumps, use classified equipment, carryout proper maintenance, etc.
The sump was reconstructed with the new design, which is now functioning well and the recommendations are being implemented in existing facilities and in all new projects.
The proposed improvements for the existing system as well as adopting the recommendations in future new drainage system can ensure the prevention of possible explosions and thereby reducing the related hazards to plant facilities/operations. Sharing of the related information among the international companies having similar facilities increases the awareness about such hidden sources of explosion in a drainage system and related pro-active mitigating measures.