bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Working Condition Diagnosis Model of Sucker Rod Pumping Wells Based on Big Data Deep Learning
Authors: Wang Xiang , He Yanfeng , Li Fajun , Dou Xiangji , Wang Zhen , Xu Hui , Fu Lipei 
Published: April 2019

Abstract
Monitoring the working conditions of the sucker rod pumping wells in a timely and accurate manner is important for oil production. With the development of smart oil fields, more and more sensors are installed on the well. The variety and volume of the monitoring data are big. The oilfield big data can be utilized to improve the diagnostic performance. In this work, we aim to utilize the big data collected during oil well production and a deep learning technique to build a new generation of intelligent diagnosis model to monitor working condition of sucker rod pumping wells. Over 5 million of well monitoring records, which covers information about one year of an oil field block, are collected and preprocessed. To show the dynamic changes of the working conditions for the wells, the overlay dynamometer card is proposed and plotted for each data record. The overlay dynamometer card stacks two dynamometer curve at different times. Based on the overlay dynamometer cards, the working conditions are divided into 30 types, and the corresponding dataset are created. An intelligent diagnosis model using the convolutional neural network (CNN), one of the deep learning framework, is proposed. By the convolution and pooling operation, CNN can extract features of an image implicitly without human effort and prior knowledge. That makes CNN very suitable for the recognition of the overlay dynamometer cards. The architecture for working condition diagnosis CNN model is designed. The CNN model consists of 14 layers with six convolutional layers, three pooling layers, and three fully connected layers. The total number of neurons is over 1.7 million. The overlay dynamometer card dataset is used to train and validate the CNN model. The accuracy and efficiency of the model are evaluated. Both the training and validation accuracies of the CNN model are over 99% after ten training epochs. The average training elapsed time for an epoch is 8909.5 seconds and the average time to diagnosis a sample is 1.3 milliseconds. Based on the trained CNN model, a working condition monitoring software for suck rod pumping well is developed. The software runs 7×24 hours to diagnosis the working conditions of wells and post warning to users. It also has a feedback learning workflow to update the CNN model regularly to improve its performance. Through 3 months of on-site test run show that the actual accuracy of the CNN model is over 90%.
High Precision Velocity Model Building Technology for Gas Cloud Areas and its Application in P Oilfield, Bohai Bay Basin
Authors: Li Wenbin , Liu Lei , Wang Jianli , Liu Xuetong 
Published: April 2019

Abstract
As we all know, accuracy of the migration velocity determines the quality of imaging results to a large extent. However, traditional migration velocity analysis methods always fail in gas cloud area due to the complex wave field and poor quality of the seismic data. Aiming at this problem, we present a high precision velocity model building technology for gas cloud areas to improve seismic imaging quality in these areas. Diving wave always appears as first arrival and its ray density satisfies inversion demand well, which makes it easy to pick up shallow information and sensitive to velocity anomalies. Thus, we build velocity model for gas cloud areas based on both diving and reflected wave. Firstly, diving wave tomography inversion is carried out to establish a high precision velocity model of shallow layers. Then we perform reflection tomography inversion to get velocity model of deeper layers with shallow layers’ velocity model above as initial input. Finally, we build the accurate velocity model of gas cloud areas successfully.
The results of real data processing in P oilfield show that the velocity model built by our method has a better precision in gas cloud areas and matches the VSP velocity better in both gas cloud areas and normal areas. In contrast to the images based on conventional reflection wave velocity model, the imaging result based on our velocity model is obviously improved. Our method is widely applicable to the study of gas cloud areas and will help the understanding and interpretation of seismic data in gas cloud areas greatly.
Cohesive Approach for High-Resolution Seismic Using Inversion & Imaging in Malaysian Carbonate Field
Authors: Bashir Yasir , Babasafari Amir Abbas , Biswas Ajay , Hamidi Rositi , Moussavi Alashloo Seyed Yaser , Tariq Janjuah Hammad , Prasad Ghosh Deva , Weng Sum Chow 
Published: April 2019

Abstract
A majority of remaining proven Oil & Gas reserves is contained by Carbonate reservoir, and much more complicated to explore as imaging of the Carbonate rocks is poor. In case of Carbonate data, seismic diffraction imaging has contributed to an enhancement in the quality of seismic but there is still lack of understanding the lithology and impedance contrast which can be defined by the seismic inversion. In contrast, to the conventional process, an integration of seismic inversion methods are necessary to understand the lithology and include the full band of frequency in our initial model to incorporate and detail study about the basin for prospect evaluation. In this paper, an integrated approch is developed for better deleniation of subsurface structure and lithologies. Seismic post stack inversion technique is applied to the Carbonate field to study Electroficies and lithofacies of subsurface strata for better and detail study of the reservoir.
Application of an Integrative New Technique on Modeling and Numerical Simulation for Fractured Reservoir Based on Unstructured Grid: A Case Study of JZS Buried Hill Reservoir
Authors: Lv Zuobin , Huo Chunliang , Ge Lizhen , Xu Jing , Zhu Zhiqiang 
Published: April 2019

Abstract
JZS oilfield is an offshore metamorphic rock fractured buried hill oilfield. It was put into development in July 2010. The overall production situation of the oilfield is good, but some problems have been exposed. The main performance is as follows: It is difficult to accurately characterize the heterogeneity of fracture space distribution; In the numerical simulation of fractured reservoir, it is impossible to accurately describe and predict the fracture flow of fluid channeling in corner point grid system.
In order to solve the above problems, this study presents a new integrated fractured reservoir geological modeling and numerical simulation research method based on unstructured grid. There are three key aspects to this method. (1) The multi-scale (large, middle and small) discrete fracture system is established by combining outcrop measurement data with well point information and seismic attributes. On the basis of post-stack 3D seismic data, ants attributes are extracted, then the ant body results are transformed into large scale fractures; Using azimuth anisotropy attribute based on pre-stack inversion and combining the distribution orientation of large-scale fractures, the middle-scale fractures are established; According to the power law distribution relation between the cumulative frequency and the fracture length of large scale and small scale which based on outcrop observation, the imaging logging data and pre-stack inversion azimuth anisotropy attribute, small scale fractures are constructed by DFN technology.(2) For multi-scale fractures, the unstructured grid division technique is used to build a 3D model that conforms to the heterogeneity of dual media. In this study, a layered triangular prism grid generation technique is proposed. It is used to establish model of multi-scale fractures based on unstructured grid. Using large-scale fractures as a constraint, full 3D unstructured grid model is set up, and the discrete fracture model can accurately describe the fracture system and the coupling relationship between matrix and the fracture;(3)The triple-medium numerical simulation of the reservoir in the study area is carried out by using the automatic history fitting technology of ensemble kalman filter (EnKF). After several parameter adjustments, both the coincidence rate of the index and the fitting precision are higher than before.
Multi-scale discrete fracture model based on the large-scale fractures discretization processing, equivalent medium processing to middle and small scale fractures, keeps the seepage characteristic of the large-scale discrete fractures model and ensures the calculation efficiency. The results show that the new method has obvious advantages in computing speed and that the fitting effect is closer to the actual production performance.
Waterflood Surveillance by Calibrating Streamline-Based Simulation with Crosswell Electromagnetic Data
Authors: Mishra Shubham , Shrivastava Chandramani , Ojha Aditya , Miotti Fabio 
Published: April 2019

AbstractOptimal exploitation of hydrocarbon reservoirs has always been a challenge due to uncertainties posed by subsurface heterogeneities that are often not factored into field development plans. Secondary and tertiary recovery mechanisms, such as waterflooding and enhanced oil recovery (EOR), are used to enhance the oilfield recovery beyond primary recovery. However, as the field development transitions to secondary/tertiary mechanisms, the challenges in monitoring these mechanisms further increase the uncertainty in field development. If these uncertainties are not reduced or incorporated properly, the field development may easily become uneconomic. This work presents a workflow that addresses the limitation of regular waterflood surveillance while characterizing the reservoir for optimal exploitation.The current technologies for waterflood surveillance are limited either to local surveillance methods, such as tracers, crosswell seismic and crosswell electromagnetics (EM), or to uncalibrated global realizations, such as full-field streamline simulation, with no validation between the wells (It is to be noted that a full-field reservoir simulation calibrated with production-injection data in defined time-interval is stated as a global-surveillance method in this paper). This workflow devises integration of an effective local waterflood monitoring method, crosswell EM, and a global waterflood modeling method, streamline simulation. The process of validating the parameters of a geological model and a dynamic model with time-lapse crosswell EM data significantly reduces reservoir characterization uncertainty and helps in the preparation of a precise dynamic model.
Identification and Analogy of Carbonate Geometries Between Offshore Indus Basin in Pakistan and Proven Carbonate Play
Authors: Khan Muhammad Hanif , Maqsood Tahir , Jaswal Tariq Majeed , Mujahid Muhammad , Malik M. Suleman , Jadoon Ehtisham Faisal , Hakeem Uray Lukman 
Published: April 2019

This article investigates the seismic reflection geometries (possible reservoir) of Paleogene of Offshore Indus Basin Pakistan (shelf area) from 2D seismic and make an analogue with the proven carbonate reservoir geometries found in countries such as Canada and Middle East.
The 2D seismic data are used to interpret the possible carbonate features and methods to identify them and define its depositional setting on the carbonate platform.
The offshore Indus Basin is tectonically a rift and a passive continental margin basin, located in Offshore Pakistan and Northwest India where carbonates were deposited on the shelf and the deep offshore area during early post-rift phase. In the deep offshore area, carbonates were set on volcanic seamounts during the Paleogene age.
In Paleogene, the Indian Plate was passing through the equator in the conditions of warmer water with appropriate water salinity, where those conditions were suitable for the growth of organisms responsible to develop reefs in the Offshore Indus area. The available seismic data analysis has indicated the possible presence of different carbonate reefs on the shelf. The seismic data enabled to define the possible carbonate Rimmed shelf depositional model in the area.
The aim of this article is to highlight and analogue carbonate seismic geometries, their internal architecture in the Paleogene interval of the Offshore Indus Basin (shelf area) and how to identify them, which may help for further exploration in Offshore Indus Basin.
Flow Enhancement by High Power Laser Technology
Authors: Batarseh Sameeh , AL Harith Abdullah , Othman Haitham , Al-Badairy Hameed 
Published: April 2019

The objective of this work is to present the utilization of high-power laser technology in different downhole flow enhancement applications. High power laser technology provides innovative non-damaging technology and is an alternative to several current downhole conventional technologies. Wide ranges of high power laser applications have been identified, evaluated and successfully tested in the laboratory, these applications are related to improve production. The precision of controlling the laser parameters enables the properties flow improvement in all rock types.
Laser energy generated and transmitted from the laser source to the target via fiber optics cables. The laser beam is controlled by downhole tool and optical bottom hole assembly. Based on the identified applications, the laser tools are designed and built combining mechanical and optical components that are aligned and assembled accordingly, the tools released the final shaped beam to the target. The controlled beam generates thermal energy, this energy can melt, vaporize or spall the formation, depending on the application needed.
High power laser technology has the potential to change the industry in several downhole applications including perforations, heating, fractures initiation, open hole notching, deep perforation, and drilling. The motivation for searching for alternative technologies is the cost effective and advancement of the laser technology and the need for none damaging environmentally friendly alternative technology. Laser provides unique advantages for downhole applications, such as accuracy, precision, and power, these parameters have been successfully tested in the lab and the optimized setting are configured in the tool. Several iterations of the tools have been done to optimize and finalize the successful design. The tools are designed to fit in slim holes as small as four inches. In addition, the tools are designed to operate in a fluid environment, the tools are equipped with purging capabilities to circulate gas or fluid, the functions of the purging are to clean the hole from the debris and carry the cuttings.
The technology provides very small footprint and is environmentally friendly, it is a waterless technology when it is used for fracturing, and a non-explosive perforation base technology when it is used as a perforation gun. The unique futures of the technology are the precision is controlling and orienting the energy in any direction regardless of the reservoir stress orientation and magnitude. The precision in orienting the energy enables to focus the energy on the pay zones directly maximizing reservoir contact.
A New Multiple Chelating Acid System with Low Damage and Weak Dissolution
Authors: Li Nianyin , Yang Ming , Zhang Qian , Zhou Hongyu , Zhai Changjin , Feng Lei 
Published: April 2019

AbstractMatrix acidizing is an essential strategy to maintain or increase productivity or injectivity of hydro-carbon wells. However, for loose sandstone reservoirs, the rock skeleton structure is easily de-stroyed by acidizing with conventional acid systems, which results in sand production. Also, the precipitation of metal fluorides, fluorosilicates, and so forth that may occur during acidizing will cause secondary damage to reservoirs. Therefore, we propose a new multiple chelating acid system (NMCAS) with low damage and weak dissolution. The system consists of multiple weak acids, organic phosphonic chelators, anionic polycarboxylic chelating dispersants, fluorides, and other auxiliary additives. Its performance was measured through laboratory tests. First, the dissolution retardation effect and dissolution capacity of NMCAS were analyzed by long-term dissolution tests. Then, the changes of particle size and mineral composition of the rock powder before and after dissolution of NMCAS and a regular mud acid system were comparatively analyzed by a sieving analysis method and x-ray diffraction measurement. Third, the chelating abilities of the system on metal ions were analyzed by a titration method. Moreover, the improvement of seepage capacity was analyzed by a core acidification flowing experiment and scanning electron microscopy. Finally, the dissolution mechanism of the system was further analyzed by energy dispersive spectroscopy. Research results indicate that NMCAS has a good retardation effect and a moderate dissolution ability. After dissolution of rock powder with the proposed acid system, the changes in particle size were less than those of the conventional mud acid system. Also, it dissolved merely a small portion of the clay minerals, but increased the dissolution of quartz, feldspar, and other matrices. NMCAS can prevent secondary precipitation of metal ions during the acidizing process because of its strong chelating ability for calcium ions, magnesium ions, and iron ions. The permeability of sample cores was moderately increased, and they formed obvious dissolution channels; however, the rock skele-ton structure was not destroyed after acidizing with NMCAS. This is because the system reduced the dissolution of clay minerals with larger specific surfaces because of the adsorption effect (a relatively lower reduction in the content of the Al element) while enhancing that of such matrices as quartz and feldspar (relatively larger changes in the content of the Si element). NMCAS can dis-solve the cement appropriately while enhancing the dissolution of the matrices, which protects the rock skeleton structure of loose sandstone reservoirs. The proposed acid solution would be of value for removing formation plugging and increasing the production of loose sandstone reservoirs.
Linking Injection-Induced Seismicity to Permeability Changes
Authors: Zhang Xi , Zhang Fengshou , Wang Shize 
Published: April 2019

AbstractThe permeability along a fracture is not constant, but varies with geometrical complexities such as pre-existing cracks. The spatial permeability changes affecting fluid pressure distributions can generate a sophisticated source mechanism potential to interpret measured seismicity complexity in the field. In this study, the relation between injection-induced seismicity and changes in fracture permeability during hydraulic fracturing stimulation of naturally fractured reservoirs is investigated numerically. In the model, the infinite homogeneous rock is assumed to be impermeable and elastic and a plane-strain fracture is embedded in it with distributed cracks. The fluid flow in the fracture is realized through over pressure generated by constant-rate injection. When the over-pressurized fluid enters these cracks, the pressure varying trend is changed and the injection pressure tends to increase, rather than decrease monotonically. Also, the slipping is temporarily stopped along the whole fracture. When the barrier to fluid flow is overcome, a most prominent pulse-type slip at a limited slip speed occurs along the pressurized region. The slip pulse can induce an injection pressure drop reflecting the decrease of the stress level near the rupture tip. In the meantime, the slip pulse acts as the source mechanisms for these microseismic events during the fracturing stimulation operations. It is found that the stress drop and slip rate decrease with rupture growth. In addition, the stopping phase and the accelerating duration of the slip patterns are two interesting features to estimate the source sizes of the rupture complexities generated by the forced fluid flow along a fracture.
Effective Annular Ledge Formation Sidetracking in Multilateral Wells in Vostochno-Messoyakhskoye Field
Authors: Voronin Andrey , Abaltusov Nikolay , Vershinin Anton , Dmitriev Aleksandr 
Published: April 2019

Abstract
Multilateral drilling technology offers a highly effective method of enhanced oil recovery in fields characterized by complicated geological structure. This paper describes the analysis of sidetracks in an open hole by annular ledge formation with the use of a downhole motor in multilateral wells in Vostochno-Messoyakhskoye field.
Since May 2018, more than 130 sidetracks have been drilled in Vostochno-Messoyakhskoye field with the use of bottomhole assembly (BHA) with a downhole motor in open hole by annular ledge formation. The fundamental difference between this method and conventional sidetracking with a downhole motor is that during sidetracking the entire drill string constantly rotates, rather than just bit rotation produced by downhole motor operation. In the process of technology introduction a comparison was made on how different downhole and geological conditions influence the time and performance results.
The technology introduction resulted in the sidetracking time reduction from 9 hours to just 3 to 4 hours.
A number of additional advantages of sidetracking with annular ledge formation were confirmed in the process of operations:
The constant rotation of the drill string enables smooth weight transfer to the bit smooth, without failures. This contributes to effective and uniform ledge formation. Such sidetracking can be carried out at an extended length of open hole when it is difficult to ensure a free movement of the BHA which is necessary of conventional sidetracking. Constant rotation mitigates the risk of differential sticking. More favorable conditions are created for BHA movement in an interval of the holes diversion and subsequently for liner running in. It is possible to sidetrack with the use of a stiff BHA including a complete set of logging tools. In case of conventional sidetracking, it is preferable to use a short and flexible BHA.
The experience gained in Vostochno-Messoyakhskoye field can be extrapolate to other fields where multilateral wells are drilled with annular ledge formation.
A Useful Application of Foam for Fast-Tracking Residual Gas Saturation Process and Reducing Leakage Risk During CO2 Injection
Authors: Adebayo Abdulrauf Rasheed 
Published: April 2019

Abstract
Carbon dioxide (CO2) storage in subsurface formations is recognized as the most effective method of permanently sequestering greenhouse gases. However, the possibility of leakage of mobile gases from the storage reservoir is a cause of environmental concern. This study aims to address this concern. A method is presented that can fast-track capillary trapping of gas during gas injection into subsurface geological formations such that a limited amount of free gas is available in case a leakage occur. The method can reduce the time scale of capillary (residual) trapping from decades to weeks. A laboratory experiment indicated that this can be achieved with foam-assisted water alternating gas (FAWAG) injection. In the laboratory setup, capillary trapping of gas was monitored in real time for every successive FAWAG cycle. The trapped gas were stable and remained trapped even after a prolonged water injection. The foaming agents added to the injected water facilitated the increased trapped gas saturation. However, high temperature and salinity significantly reduced the effectiveness of the foam. The type or composition of the injected gas also affect the effectiveness of the foam. The foam is most effective in N2 or N2-rich gas compared to CO2 gas. This was due to the low interfacial tension between the CO2 and the foaming solution. Improvement in foam effectiveness in high temperature high salinity and low IFT environment is much possible as ongoing research works indicate.