bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water Injection Profiling Using Fiber Optic Sensing by Applying the Novel Pressure Rate Temperature Transient PTRA Analysis
Authors: Al-Hashemi Mohammed , Spivakovskaya Daria , Moes Evert , Panhuis Peter in ‘t , Hemink Gijs , Shako Valery , Kortukov Dmitry 
Published: December 2021

Abstract
Fiber Optic Systems, such as Distributed Temperature Sensing (DTS), have been used for wellbore surveillance for more than two decades. One of the traditional applications of DTS is injectivity profiling, both for hydraulically fractured and non-fractured wells. There is a long history of determining injectivity profiles using temperature profiles, usually by analyzing warm-back data with largely pure heat conduction models or by employing a so-called "hot-slug" approach that requires tracking of a temperature transient that arises at the onset of injection. In many of these attempts there is no analysis performed for the key influencing physical factors that could create significant ambiguity in the interpretation results. Among such factors we will consider in detail is the possible impact of cross-flow during the early warm-back stage, but also the temperature transient signal that is related to the location of the fiber-optic sensing cable behind the casing when the fast transient data are used for interpretation such as the "hot slug" during re-injection.
In this paper it will be shown that despite all such potential complications, the high frequency and quality of the transient data that can be obtained from a continuous DTS measurement allow for a highly reliable and robust evaluation of the injectivity profile. The well-known challenge of the ambiguity of the interpretation, produced by the interpretation methods that are conventionally used, is overcome using the innovative "Pressure Rate Temperature Transient Analysis" method that takes maximum use of the complete DTS transient data set and all other available data at the level of the model-based interpretation. This method is based on conversion of field measurements into injectivity profiles taking into account the uncertainty in different parts of the data set, which includes the specifics of the DTS deployment, the uncertainty in surface flow rates, and possible data gaps in the history of the well.
Several case studies will be discussed where this approach was applied to water injection wells. For the analysis, the re-injection and warmback DTS transient temperature measurements were taken from across the sandface. Furthermore, for comparison, injection profiles were also recorded by conventional PLTs in parallel.
This case study will focus mostly on the advanced interpretation opportunities and the challenges related to crossflow through the wellbore during the warm-back phase, related to reservoir pressure dynamics, and finally related to the impact of the method of DTS deployment. In addition to describing the interpretation methodology, this paper will also show the final comparison of the fiber-optic evaluation with the interpretation obtained from the reference PLTs.
Novel Sand Conglomeration Treatment Prevents Sand Production and Enhances Well Productivity: Offshore Caspian Case Study
Authors: Kalabayev Ruslan , Sukhova Ekaterina , Rovshenov Gadam , Gurbanov Guvanch , Gil Joel , Kontarev Roman 
Published: December 2021

Abstract
Many oil producing wells, globally, experience sand production problems when reservoir rock consists of unconsolidated sand. Several wells in the Dzheitune oil field are experiencing a similar challenge. Production of formation fines and sand has caused accumulation of fill and wellbore equipment failures and has necessitated periodical and costly coiled tubing-assisted wellbore cleanout operations. A novel chemical treatment tested in the oil field to tackle the challenge led to positive results.
A well with a relatively short target perforation interval was selected as a candidate for the trial sand conglomeration treatment to avoid any uncertainties related to zone coverage. Pre-requisite sand agglomeration and chemical-crude oil compatibility laboratory studies were carried out to optimize the main system and preflush fluid formulations. Once the laboratory testing was complete, a step-rate test was performed to determine the maximum injection rate below formation fracturing pressure. The chemical systems were prepared using standard blending equipment. The preflush fluid was injected to prepare the treated zone. The main fluid was then injected into the reservoir in several cycles at matrix rate by a bullheading process. Upon completion of the treatment, the well was shut in for several days for optimal agglomeration (conglomeration) before the well was slowly put on production.
A long-term increase in the productivity index and sand-free flow rate with no damage to the wellbore or the reservoir were observed. The technology demonstrated its efficiency in preventing and controlling sand production; avoiding frequent, time-consuming, costly wellbore cleanout operations; and producing hydrocarbons at reduced drawdown pressure.
Recent Advances in Supercritical CO2 Fracturing: New Theory, New Technology, and Application
Authors: Duan Wenguang , Sun Baojiang , Pan Deng , Xu Jianchun , Liu Jian 
Published: December 2021

Abstract
The shale oil reservoir in Jimusaer has the characteristics of low porosity and low permeability, resulting in significant resistance in oil flow compared with conventional oil reservoirs. Fracturing is needed to increase shale oil production. Supercritical CO2 (SC-CO2) is an ideal choice for fracturing fluid due to its unique physical and chemical properties. SC-CO2 fracturing is able to make CO2 flow into microfractures and greatly reduce the pumping pressure. New progress has been made in the application of the supercritical CO2 fracturing technology in Jimusaer.
A phase control model of SC-CO2 fracturing as a function of temperature and pressure is established, which takes into account the SC-CO2 features, intrinsic energy, flow behavior in fracture and fluid filtration. In this paper, the influences of injection pressure and temperature, injection rate, temperature-pressure field, temperature gradient, and phase behavior are analyzed extensively, in addition, the phase control model and its chart of fracture are presented.
The proppant accumulation height reduces by a small amount with the increase of the fracturing fluid injection rate. It is necessary to improve the proppant pumping technology by the sand embankment section and proppant concentration. The liquid transforms into supercritical fluid, when flowing in wellbores and fractures. Different fractures have different phase points, and a lower injection temperature is affected by higher injection rate, lower temperature gradient and closer position from transformation point to the end of fracture. Therefore, in order to achieve a better fracturing effect, the injection temperature, pressure, and rate need to be optimized by surface equipment according to the reservoir conditions, to control the phase behavior of CO2.
We built a phase control model for the SC-CO2 fracturing technology, which considers temperature control. We also developed some new techniques to improve SC-CO2 fracturing which is critically needed in the Jimusaer oilfield.
A Real-Time Friction Prediction Model for in Service Drill String Based on Machine Learning Methods Coupling with Mechanical Mechanism Analysis
Authors: Guo Huijuan , Luo Huaidong , Zhan Guodong , Wang Baodong , Zhu Shuo 
Published: December 2021

Abstract
With highly deviated wells and horizontal wells are widely used in the oil industry. The large slope well sections and long horizontal well sections will lead to a sharp increase of the drill string torque and friction, which may reduce the drilling efficiency, and even lead to accidents. Therefore, real-time and accurate analysis of drill string’s torque and friction is an urgent problem facing by the modern drilling technology. The paper established a real-time friction prediction model that combines machine learning methods with drill string mechanical mechanism analysis model. Based on 84000 sets of field monitoring data obtained on-site, a regular data training set for weight on bit (WOB) and torque prediction was constructed with 23 types of time-series related parameters and 10 types of timing independent parameters. Relationships between time-series related parameters and timing independent parameters with the weight on bit and torque were trained to utilize long and short-term memory (LSTM) neural network and muti-layer back propagation (BP) network respectively. The new developed LSTM-BP neural network achieves high-precision prediction results of WOB and torque with a relative error of less than 14%. Based on derived WOB and torque prediction results, a theoretical mechanical analysis model of the entire drill string was adopted in this paper to develop the quantitative relation between WOB and torque with the friction coefficient of the drill string and oil casing. Suitable friction coefficients along the drill string can be finally obtained by solving the equilibrium function between predicted WOB, torque and measured hook load, rotary-table torque via an iteration algorithm. A case study was performed finally using the proposed intelligent analysis method to calculate the friction coefficients. This proposed methodology can be referenced to decrease the sticking risks and improve the drilling efficiency, which can finally increase the extension limit of horizontal wells in complex strata.
New Generation of Ultra-High Definition Directional Propagation Resistivity for Real Time Reservoir Characterization and Geosteering-While-Drilling
Authors: Sun Keli , Thiel Michael , Mirto Ettore , Tan Sarwa , Liu Jianguo , Feng Yao , Harms Kent , Nesttun Øyen Beate , Pham Tom , Veeraiah Ashwin , Toghi Farid , Liu Ruixia , Wang Hui , Denichou Jean-Michel , Wibowo Vera Krissetiawati , Wang Haifeng , Wang Fei , Snovida Zoriana , Beltran Gil Eliana Carolina , Pinzón Perez Joaquín , Antolinez Delgado Hernan Javier , Liu Wenyu , Wang Jianfu , Omeragic Dzevat 
Published: December 2021

Abstract
Over the last two decades, the continuing integration of distance-to-boundary logging while drilling (LWD) workflows with the directional drilling processes, has dramatically improved geosteering of deviated and horizontal wells. However, the interpretation of underlying propagation azimuthal electromagnetic measurements has remained challenging in complex thin and multi-layered geologies.
Recent technology advancements in LWD electromagnetic propagation resistivity coupled with significant software enhancements provide an opportunity for improving the formation evaluation to reduce wellbore position uncertainty, accurately detecting physical parameters such as layer resistivity and anisotropy, formation dip and azimuth.
A newly developed multilayer mapping-while-drilling service with full azimuthal sensitivity is introduced for use in geosteering and formation evaluation while drilling applications. The tool offers the industry's first combination of axial, tilted and transverse antennas to produce a complete measurement set to enable the interpretation of complex and anisotropic formation. Advanced application algorithms are used to calculate a high-definition map of the formation providing horizontal and vertical resistivity (anisotropy), as well as dipping angle and azimuth. Furthermore, the tool can provide deep resistivity borehole images while drilling in real time.
The new measurement set, more comprehensive than any other directional propagation resistivity tool in the industry, is discussed in detail. The measurements, combined with a new deterministic inversion, enable reconstruction of the resistivity of up to eight formation layers, and significantly outperforms existing directional propagation resistivity services.
The new measurements and data processing workflow are demonstrated with several synthetic and field data. Examples show that this newly developed tool can provide a reliable two-in-one service: geosteering and advanced formation evaluation.
Development of Novel Shale Swelling Inhibitors Using Hydrophobic Ionic Liquids and Gemini Surfactants for Water-Based Drilling Fluids
Authors: Khan Rizwan Ahmed , Murtaza Mobeen , Ahmad Hafiz Mudaser , Abdulraheem Abdulazeez , Kamal Muhammad Shahzad , Mahmoud Mohamed 
Published: December 2021

Abstract
In the last decade, hydrophilic Ionic liquids have been emerged as an additive in drilling fluids for clay swelling inhibition. However, the application of hydrophobic Ionic liquids as a clay swelling inhibitor have not been investigated. In this study, the combination of hydrophobic Ionic liquids and Gemini surfactant were studied to evaluate the inhibition performance.
The novel combination of hydrophobic ionic liquid (Trihexyltetradecyl phosphonium bis(2,4,4-trimethyl pentyl) phosphinate) and cationic gemini surfactant (GB) was prepared by mixing various concentrations of both chemicals and then preparing water based drilling fluid using other drilling fluid additives such as rheological modifier, filtration control agent, and pH control agent. The wettability of sodium bentonite was determined by contact angle with different concentrations of combined solution. Some other experiments such as linear swelling, capillary suction test (CST) and bentonite swell index were performed to study the inhibition performance of ionic liquid.
Different concentrations of novel combined ionic liquid and gemini surfactant were used to prepare the drilling fluids ranging from (0.1 to 0.5 wt.%), and their performances were compared with the base drilling fluid. The wettability results showed that novel drilling fluid having 0.1% Tpb-P - 0.5% GB wt.% concentration has a maximum contact angle indicating the highly hydrophobic surface. The linear swelling was evaluated over the time of 24 hours, and least swelling of bentonite was noticed with 0.1% Tpb-P - 0.5% GB wt.% combined solution compared to linear swelling in deionized water. Furthermore, the results of CST also suggested the improved performance of novel solution at 0.1% Tpb-P - 0.1% GB concentration. The novel combination
The novel combination of hydrophobic ionic liquids and gemini surfactant has been used to formulate the drilling fluid for high temperature applications to modify the wettability and hydration properties of clay. The use of novel combined ionic liquid and gemini surfactant improves the borehole stability by adjusting the clay surface and resulted in upgraded wellbore stability.
A Successful Field Application of Polymer Gel for Water Shutoff in a Fractured Tight Sandstone Reservoir
Authors: Wu Qianhui , Ge Jijiang , Ding Lei , Wei Kaipeng , Liu Yuelong , Deng Xuefeng 
Published: December 2021

Abstract
The wide existence of fractures makes conformance control by polymer gels more challenging in water-flooded oil reservoirs. Selection of an applicable gel system and design of an intelligent approach for gel treatment are key components for a successful field application. Moreover, selecting the candidate wells and determining the injection volume of gel are also critical to the success of gel treatments.
A gel system with adjustable polymer concentrations was applied for conformance control in fractured tight sandstone reservoir, and notably, less than 5% of syneresis was detected after aging for one year at reservoir condition. The viscosity and the gelation time of this gel system can be adjusted according to the targeted reservoir conditions. The pilot test was conducted in Huabei oilfield (China), and the oil recovery after water flooding was only about 20% original oil in place (OOIP). With further exploitation of the oil field, the majority of the reservoir has suffered from poor sweep efficiency and extremely high water cuts. To characterize the distribution of fractures, the seismic coherence cube was utilized. In addition, the pressure transient test, interwell tracer test and the injection-production data were used collaboratively to determine the volume of fractures in the reservoir. The option of gel formulation and the determination of operational parameters are mainly based on the wellhead pressure.
According to the seismic coherence cube, the zone of candidate well group shows a weak coherence state, indicating that numerous fractures exist. Furthermore, there is good continuity between the candidate injection well and the production well. According to the pressure transient test, the volume of re-open fracture is about 1730.9 m3, while the volume of micro-fracture is about 4839.4 m3. Comparably, based on the interwell tracer test, the estimated volume of fractures is approximately 3219.7 m3. Consequently, the designed volume of gel for treatment is 1500.0 m3 in total. The properties of gel slugs were carefully designed, which was tailored to the specific wellbore conditions and formation characteristics. Three months after the gel treatment, the average oil production was increased from 0.36 t/d to 0.9 t/d, and the water cut was decreased from 95.77% to 88.7%. The improved oil production was still benefited from this gel treatment after one year.
This study provides a comprehensive approach, from optimization of gel formulation, followed by selection of candidate wells, to calculation of the injected volume, to design the viable operational parameters, for gel treatment field application in fractured reservoirs. It shows that, besides a gel system with superior properties, a suitable injected volume of gel may enhance the chance of success for gel treatments.
Minimizing Carbon Footprint by Smart Sustainable Reservoir Management
Authors: Katterbauer Klemens , Marsala Alberto , Al Qasim Abdulaziz , Yousif Ali 
Published: December 2021

Abstract
Sustainability and reducing carbon footprint has attracted attention in the oil and gas industry to optimize recovery and increase efficiency. The 4th Industrial Revolution has made an enormous impact in the oil and gas industry and on analyzing carbon footprint reduction opportunities. This allows classification of various reservoir operations, installation of permanent sensors and robots on the field, and reduction of overall power consumption.
We present an overview of new AI approaches for optimizing reservoir performance while reducing their carbon footprint. We will outline the significant carbon emissions contributors for field operations and how their impact will change throughout the production's lifecycle from a reservoir. Based on this analysis, we will outline via an AI-driven optimization framework areas of improvement to reduce the carbon footprint considering the uncertainty.
We analyzed the framework's performance on a synthetic reservoir model with several producing wells, water, and CO2 injecting wells. Beneficial in reducing carbon emissions from the field is the reuse and injection of CO2 for enhancing hydrocarbon production from the reservoir. One hundred different scenarios were then investigated utilizing an innovative autoregressive network model to determine the impact of these components on the overall carbon emission of the field and determine its uncertainty. The conclusions from the analysis were then incorporated into a data-driven optimization routine to minimize carbon footprint while maximizing reservoir performance. The final optimization results of the showcase outlined the ability to reduce the carbon footprint significantly.
Monitoring Dynamic Water Injection to Improve Oil Recovery Efficiency
Authors: Al Hamad Mohammed , Zhang Ping , AlZoukani Ahmad , Altundas Bilgin , Abdallah Wael 
Published: December 2021

Abstract
Dynamic water, also known as smart water, injected at the end of conventional water flood by seawater, is known to show significant improvement in recovering additional oil. Different mechanisms have been proposed and lab measurements were conducted to understand the underlying process of additional oil recovery through dynamic water injection in lab conditions. In this work, we study the effects of different dynamic water injection scenarios on oil recovery in carbonate reservoirs based on reservoir simulations using representative fluid and rock properties with relative permeability curves obtained from core studies. To quantify the changes in measurable multiphysics properties due to dynamic water injection and reconcile multiphysics interpretation with additional oil recovery at field scale, a petrophysically consistent multiphysics effective property modeling is conducted. Based on the simulation results, dynamic water injection is shown to be effective in additional oil recovery at field scale post seawater injection. In addition, saturation changes caused by dynamic water injection result in detectable time-lapse contrast in the corresponding conductivity profiles, suggesting feasibility of the resistivity measurements to monitor dynamic water injection. This paper shows the advantages and benefits of petrophysically consistent multiphysics effective property modeling for a successful fluid monitoring design for quantifying the efficiency of dynamic water injection on additional oil recovery post seawater flood.
Multi-horizon Simultaneous Tracking Based on Dynamic Seismic Waveform Matching
Authors: Chen Maoshan , Wan Zhonghong , Wang Changhong , Liu Jingyan , Chen Zhaoqin 
Published: December 2021

Summary
Due to the rapid increase in the amount of seismic volumes, the traditional seismic interpretation mode based on manual structure interpretation and single-horizon automatic tracking has encountered many challenges. The seismic interpretation of large or super-large 3-D seismic surveys is facing serious accuracy and efficiency bottlenecks. Aiming to the goal of improving the accuracy and efficiency of seismic interpretation, we propose a dynamic seismic waveform matching technology based on the sparse dynamic time warping algorithm under the guidance of the relative geological time volume theory, and realize multi-horizon simultaneous tracking based on the technology. Has been verified by a model and a real seismic volume, it can realize simultaneous horizon automatic tracking, full spatial tracking and high-density tracking, and can significantly improve the accuracy and efficiency of structure interpretation.