bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comprehensive Approach to Achieve Record Performance on the field named after V. N. Vinogradova
Authors: Yakunin Sergey , Kashin Evgeniy , Shtyfel Alexandr 
Published: October 2018

Abstract
JS "RITEK" since 2008 engaged in the development of deposits named after V. N. Vinogradova. Geological oil reserves are more than 100 million tons of oil and are hard to recover reserves. Target horizon is AS3. Development of the field. V. N. Vinogradov was carried out in several stages. The first stage took place at the end of 2008 and involved the well re-entry and re-testing of exploration wells of the field. The next stage was the drilling of horizontal wells with multi-stage hydraulic fracturing. The horizontal wells have the standard design: direction Ø324 mm – 50 m, conductor Ø245 mm – 800 m, production casing Ø178 – 2000 m and a liner with a long horizontal section Ø114 mm – 500 m. Over the past few years the development of the field, the length of the horizontal section increased from 500 m to 1600 m. For the successful drilling of wells with horizontal section of 1600 metres was conducted the work on optimization of equipment, technologies and parameters of drilling a conductor casing string and the shank. The article presents technical and technological solutions for drilling optimization.
Innovative Solution for Fluid Loss in Sub-Hydrostatic Wells During Workover Operation-Case Study from Kuwait.
Authors: Hassan Mohammad , Nour Ahmad , Al-Yaqout Thanyan , Agarwal Chakshu , AL-Mejmed Saad , AL-Saleh Fawaz , AL-Shammari Yousif , AL-Hazeem Fatema , AL-Khatrash Mouzah , Safar Emad , Hassan Ahmad 
Published: October 2018

Abstract
Fluid loss in sub-hydrostatic wells during overbalanced workover operation is a significant concern and includes three different challenges. The first challenge is the near wellbore damage due to the invasion of the completion fluid to the formation. The second challenge is the additional operating cost associated with both rig time spent to pump fluid into the well and stimulation treatment to restore the initial formation condition. The third challenge is maintaining a safe window of overbalance condition during the workover operation which is a major HSE & well integrity concern.
The outmoded technique to control losses is to use solids base fluid which could damage the formation if not properly removed after the treatment. Also, in some cases it requires an acid breaker to restore the original formation state. The acid treatment must be done before installing the pump in hole as the solid-fluid system can't be flow back through the artificial lift.
KOC keeps the safety window of the overbalance by pumping completion fluid (brine) into the well while killing operation. As a consequence, rig had to pump hundreds of bbls of brine into most of the depleted reservoirs which in most of the cases causes sever wellbore/reservoir damage (major concern) leading to delay in Production and increase in operation cost associated with rig time and completion fluid cost.
Customised Salt Pill system is a unique solution for such challenge, and it had been proved trouble-free globally by sealing the face of the formation during the killing operation. Recently the salt pill system was deisgned and deployed in a well in one of KOC brown fields, the job magnificently compiled with KOC success criteria safely. Moreover, the fluid level was static in the well during the entire workover operation. With the successful flow back for the well after ESP installation, demonstrated no wellbore damage with salt pill even without requiring any breaker nor acid.
The application of Salt Pill was successful and it lead to saving of approximately two days of rig time and Early Production from the well without damaging the reservoir with the invasion of completion fluid. This innovative solution has opened the way forward for KOC to implement same technology in other sub-hydrostatic wells.
Fit-for-Purpose Water Treatment in Permian Shale – Field Data, Lab Data and Comprehensive Overview
Authors: Walsh John , Sharma Ramesh 
Published: October 2018

Abstract
Sourcing water for hydraulic fracturing and disposing of produced water are well-known constraints and significant cost items in the development of shale formations in the Permian Basin. Utilizing a water life-cycle approach, some of the produced water can be treated and reused. However, there is usually more produced water than needed and some must be disposed, typically by injection into a disposal well. Whether the water is to be reused or disposaed, it must be treated to some extent. Given the volumes of water involved, treatment technology must be robust and inexpensive. This suggests that the selected technology should be tailored to the characteristics of the water and the quality requirements of the final purpose (reuse or disposal).
This paper starts with characterization of produced water from a few Permian shale fields and proceeds to the selection of appropriate conventional, robust and low cost treatment systems. Using this approach, fit-for-purpose treatment systems have been implemented in the field. Impairment problems with reuse and disposal of this treated produced water have decreased.
Effect of GOR on Gas Diffusivity in Reservoir Fluid Systems
Authors: Ratnakar Ram R. , Dindoruk Birol 
Published: October 2018

Abstract
Molecular diffusion plays a dominant role in various reservoir processes, especially in the absence of convective mixing. In general, gas diffusion in oils depend on several factors such as pressure, temperature, oil viscosity and gas-to-oil ratio (GOR). Out of these factors, GOR effects/live oil compositional changes on diffusivity is rare or not available in literature. The current work fills this gap and present the experimental observations on the effect of GOR on gas diffusivity in reservoir fluid systems.
Synthetic live oils were created by combining stock tank oil (STO) and methane in various ratios. Constant composition Expansion (CCE) experiments were performed with these oils to obtain their bubble points and liquid-densities in relation to GOR. Methane diffusivity in these oils were obtained from pressure-decay tests at high temperature/pressure conditions. The diffusion and solubility parameters were estimated from pressure-decay data using the diffusion model and integral-based linear regression presented in the previous works ([1]-[2]). The experimental and modeling methodology are presented here in sufficient detail to allow readers to replicate and evaluate the results.
In this work, we have experimentally investigated the effect of GOR on methane diffusivity in oils at high temperature/pressure conditions using pressure-decay tests. In particular, We present experimental data for bubble-points and liquid density of synthetic oils having various GOR-values. For the range of GOR's considered, these measurements show that the bubble-point pressure increases linearly with GOR.Late transient solution of the pressure-decay model was utilized to obtain diffusivity parameters by regressing against experimental data. It is found that as GOR-value increases (i.e. when oil becomes lighter), the diffusivity-value increases, which is in accordance with Stokes-Einstein relation.Most importantly, an empirical correlation is developed based on limited data set to describe the variation in diffusivity values with GOR. This can be very important when experimental data for the STO is available but not for the live oils. It can also be extremely useful in gas injection processes where amount of gas dissolved in the oil varies leading to variations in diffusivity as well.
An Experimental Study for the Using of Nanoparticle/VES Stabilized CO2 Foam to Improve the Sweep Efficiency in EOR Applications
Authors: Farid Ibrahim Ahmed , Nasr-El-Din Hisham 
Published: October 2018

Abstract
CO2 foam has been used to improve the sweep efficiency for EOR as a replacement for polymers to avoid potential formation damage. Foams degrade at high temperatures (&gt;212°F), in high-salinity environments, and in contact with crude oil. The present work evaluates nanoparticles and viscoelastic surfactants (VES) to improve foam stability when these foams are used as EOR fluid.
This study investigates the stability of alpha olefin sulfonate (AOS) foam for different foam solutions in the presence of nanoparticles and viscosifiers (VES). To achieve this objective, foam stability tests were conducted at different temperatures up to 150°F. Foam stability was studied in a high-pressure view chamber (HPVC) to find the optimal. Single and dual-coreflood experiments were conducted at 150°F to investigate the divergent ability for the foam solutions on heterogonous sandstone formations. Boise and Berea sandstone cores with permeability contrast of 10-15 were saturated initially with a dead crude oil. The CO2 foam was injected with 80% quality as tertiary recovery mode. The oil recovery and the pressure drop across the core were measured for the different foam solutions.
Adding silica nanoparticles (0.1 wt%) of size 140 nm and viscoelastic cocamidopropyl betaine surfactant (cocobetaine VES) (0.4 wt%) to the AOS (0.5 wt%) solution improves foam stability. In contact with crude oil, unstable oil-in-water microemulsion generated inside the foam lamella that decreased foam stability. A weak foam was formed for AOS solution, but the foam stability increased by adding nanoparticles and VES. From the single coreflood experiments, the oil recovery from the conventional water flooding 47% of the original oil-in-place. AOS was not able to enhance the oil recovery. No more oil was recovered by AOS foam, however, extra oil was recovered in the presence of nanoparticles (19 %) and VES (26%). The dual-coreflood experiments revealed low sweep efficiency during the water flooding as a secondary recovery. Adding nanoparticles and VES to the AOS foam system increased the sweep efficiency and increased the oil recovery from the low permeability cores.
Nanoparticles and VES were able to improve the foam stability for AOS solution. Adding nanoparticles is highly recommended for EOR applications, particularly at high temperatures.
Pulsed Neutron Advances in Through-Casing Evaluation of Multilayered Reservoirs: Case Studies in the Mature Fields of the San Jorge Gulf Basin, Argentina
Authors: Maza Daniel , Oggier Fabian P. , Do Nascimento Carlos , Saldungaray Pablo J. , Zambrano Rafael , Mosse Laurent , Anci Pablo B. , Barrionuevo Pablo 
Published: October 2018

Abstract
An alternative technique to evaluate layered formations through casing in the Golfo San Jorge basin in Argentina is presented. The proposed methodology is based on pulsed neutron spectroscopy logs to assess the lithology and evaluate the hydrocarbon type and potential using resistivity-independent methods.
The basin's layered reservoirs present multiple challenges for resistivity-based methods, including low and variable formation water salinity, intricate pore systems affecting the rock electrical parameters, fine sediments with high irreducible water content suppressing the resistivity response, and high-resistivity tuffaceous sands not associated with hydrocarbons. In cased holes, simple correlations of resistivity and capture cross-section (sigma) or other techniques emulating openhole logs from basic pulsed neutron logs (PNL) can be used for interwell correlations, but are frequently inconclusive for assessing hydrocarbon potential. Our approach takes advantage of latest-generation PNL tools’ multiple measurements to reduce the uncertainty of water saturation assessment.
The proposed methodology was tested with two new-generation PNL tools, which feature high-resolution detectors that provide elemental concentrations for better understanding mineralogy including direct measurement of the carbon concentration for a reliable estimation of total organic carbon (TOC), which is directly associated with the oil volume in the pore space. The first tool was originally intended for openhole logging and has a single large detector for high-quality spectroscopy analysis. The second device is a multiple-detector slim PNL tool, which, besides the TOC and other spectroscopy outputs, also provides sigma and neutron porosity and measures a new property, the fast neutron cross section (FNXS), which is useful to detect and quantify gas. The presented case studies include examples of application with both tools in new wells and workovers. More than 20 sands, typically 2- to 5-m thick, interbedded with thick shales, were counted over the 1000- to 1500-m zone of interest, and all the data could be acquired in an acceptable time frame in spite the long intervals. The log data were complemented with the mud logging information and/or correlations from the static geological model. In all cases, we achieved good correlation between the zones with TOC, the static model, and well test results.
This experience illustrates the adaptation and application of new technologies to the development of mature fields where conventional openhole resistivity-based analysis is ambiguous. Future tasks include adjusting the technique for quantitative analysis and its use in deeper, more challenging, unconventional reservoirs in the basin.
Using Data Analytics to Assess the Impact of Technology Change on Production Forecasting
Authors: Male Frank , Aiken Chastity , Duncan Ian J. 
Published: October 2018

Abstract
The nature of well completions in the oil and gas industry continues to evolve. Although the effects of completions and spacing on initial production are well reported, how they affect ultimate recovery and terminal decline is not well understood. Over the last decade, drilling on multi-well pads has become prevalent, spacing between horizontal wells has decreased, and hydrofracture intensity has increased. These developments have decreased drilling and completion costs, while increasing initial well production. Yet, the impact of the timing, spacing, and intensity of fracturing on terminal decline rates and ultimate recovery has not been systematically investigated.
In this paper, Bakken well production profiles are used to evaluate the impact of differences in completion design on the nature of long-term production decline. To evaluate these effects, production for 12,000 Bakken wells were forecast using a physics-based approach. Using descriptive statistics and advanced visualization, terminal decline rate and ultimate recovery parameters are found to depend upon date of well completion, volumes of proppant and water injected, lateral length, and well spacing. We utilize a tree-based machine learning approach to test predictability of completion parameters on terminal decline rate and estimated ultimate recovery.
Our analyses show that pad drilling and increased hydrofracture intensity are apparently associated with small increases in initial production rates but have led to larger terminal decline rates. For example, in the Bakken, the terminal decline rate increases by upwards of ten percentage points for wells with modern completions in multi-well pads. Since production life is dependent upon terminal decline rates, spacing and completions effects must be accounted for in type curves for wells in multi-well pads.
Low Pressure - Condensate Recovery System LP-CRS. Creating Value Through Waste
Authors: Mohd Ismail Elmi , Rajah Benny , Suppiah Arul Jothy , Mat Ghani Shuhaimi 
Published: October 2018

Abstract
As a responsible and sustainable national oil company, the Malaysian Petroleum Management (MPM) of PETRONAS is committed to supporting the Paris Agreement via reduction of global Green House Gas (GHG) emissions by focusing on hydrocarbon flaring and venting optimization as a national agenda.
For fields with no means of gas evacuation or reinjection, complying with this national agenda would result in further capital investment for facility improvements or risk curtailment in production that would impact the oil revenue.
To realize the reduction of GHG footprint and generate value from condensate recovered from flaring and venting, a patented technology called ‘Low Pressure - Condensate Recovery System’ (LP-CRS) is applied. The LP-CRS is patented under NGL Tech Sdn Bhd and was jointly developed with Vestigo Petroleum Sdn Bhd under the guidance of Malaysia Petroleum Management (MPM) of PETRONAS.
A pilot LP-CRS deployed in an offshore Sarawak field in 2016 has proven to deliver significant reduction in GHG (CO2) emissions by more than 25% while recovering more than 100bbls/MMscf. These contributed to USD 7 million/year of additional value from a field with less than 30MMstb of recoverable reserves. The relatively simple operation and low maintenance of the modular LP-CRS, combined with its compact and lightweight build, makes the pilot technology attractive for replication in other offshore installations.
As part of future expansion plans, the LP-CRS has been earmarked for facilities that reinject gas for pressure maintenance and onshore gas terminals where complete gas processing facilities are not available.
Leakage Analysis and Structure Optimization of Sliding Vane Pump for Oil Recovery
Authors: Wang Shuolong , Wu Xiaodong , Han Guoqing , Ren Zebin , Tang Jingfei , Wang Hanlu 
Published: October 2018

Abstract
Sliding vane pump (SVP) is a new type of all-metal rotary hydraulic pump, which is applied to high-temperature thermal recovery wells possessing high pump efficiency. A leakage model based on the mechanical structure of SVP is presented that employs the principles of fluid dynamics. The leakage gaps of each pump chamber are divided into three parts: the gap between vane and vane slot, the gap between vane and the upper and lower valve plate, and the gap between vane tip and stator inner wall. According to the flow characteristics of fluid in each gap, the correlation equations are established from the perspective of shear and pressure difference respectively. Meanwhile, the optimum allocation of SVP is provided via comparing different structure parameters of pump on the basis of operating characteristic, including stator-rotor eccentricity, rotor-groove radius and vane parity. The significant new finding shows that the greater stator-rotor eccentricity, the greater delivery capacity of SVP, and the disequilibrium of the bearing increasing simultaneously. Therefore, the application of stator-rotor eccentricity in oil field should take into account multiple factors, such as well structure and production mode. Moreover, on the premise of meeting the requirement of pump weight and sand control, rotor-groove radius should be minimized to reduce the adverse effect on volume efficiency. Furthermore, the more vanes of SVP, the smaller period, and the greater average value of instantaneous flow rate. The flow pulsation of SVP with odd vane number is less than it with even vane number, and the recommended number of vanes is 5 to 8.
Phase Equilibrium of Hydrocarbons Confined in Nanopores from a Modified Peng-Robinson Equation of State
Authors: Cui Xiaona , Yang Erlong , Song Kaoping , Huang Jingwei , Killough John , Dong Chi , Liu Yikun , Wang Keliang 
Published: October 2018

Abstract
Phase behavior of hydrocarbons in confined nanopores is quite different from that of the bulk. In confined space, the high capillary pressure between vapor phase and liquid phase, and depressed critical properties under confinement will all affect the in-situ phase behavior. According to the theory of adsorption-induced structural phase transformation in nanopores, we modify the molar volume term of the Peng-Robinson equation of state (PR-EOS) by considering the reduced mole number of fluids caused by absorption to describe the phase behavior of fluids under confinement. Then capillary pressure is coupled with phase equilibrium equations, and the resulting system of nonlinear fugacity equations based on the modified PR-EOS is solved to present a comprehensive examination of the effect of capillary pressure and confinement on saturation pressures. Binary mixtures of methane with heavier hydrocarbons and a real reservoir fluid from the Eagle Ford confined at different pore sizes are considered. The effect of capillary pressure and confinement on the phase envelop shifts are compared.
The modified PR-EOS show that there exists a linear relationship between critical temperature shift and pore size reductions, a quadratic relationship between critical pressure shift and pore size reductions which are consistent with the experimental and molecular simulation results. The shift in the phase envelop of binary mixtures and Eagle Ford fluids show that both the capillary pressure and confinement decrease the bubble point pressures, while they oppositely influence dew point pressures. It is worthy to be noted that the effect of capillary pressure on phase envelop shifts will be suppressed when taking the critical point shifts caused by confinement into consideration. For Eagle Ford fluids, the effect of confinement on phase envelop shift is dominant compared with that of capillary pressure, and the capillary pressure cannot be overlooked when pore radius decreases to 50 nm. While the confinement begins to play an important role on the saturation pressures when pore radius decreases to 100 nm.
In addition, the methodology presented in this study can be extended to the phase equilibrium calculations of multiple pores since the modified PR-EOS can provide a consistent phase behavior description of fluid molecules over the whole range of pore sizes.
Oscillation Rheology of Dilute and Semi-Dilute Paraffin Wax Suspensions: A Novel Method to Study Wax Deposition Under Static and Quasi-Static Conditions
Authors: Smith Rashod , Miller Amanda , Mahmoudkhani Amir 
Published: October 2018

Abstract
As shale exploration has become more prevalent, producers are encountering more cases of shale oil with a high amount of paraffin content. With this introduction of paraffin wax, there are a number of challenges arise that include deposition of paraffin wax at well bore, in production tubings, chokes & valves, flow lines, separator and storage tanks which extend further down the pipelines to the refineries. With the growing demands in the global oil market for production optimization and cost reduction there is an increasing pressure for producer's and service companies to accelerate innovation in flow assurance and to deliver necessary best in class performance. While there have been great strides in treatment knowledge and method development in order to screen and optimize products under laboratory flow conditions, none are capable of simulating and measuring wax deposition under static or quasi-static conditions. These normally occur during annular flow, shut-in times, batch production and storage period. Our aim was to develop a simple, yet versatile technique to study deposition and control for dilute and semi dilute paraffin wax suspensions in condensates and model crudes comprising field paraffin waxes.