bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent Enhancements for Coiled Tubing Descaling Treatments in Middle East
Authors: Alduaij Ahmed. N. , Al-Bensaad Zakareya , Espinosa Mauricio , Ahmed Danish , Dehingia Madhurjya 
Published: September 2021

Abstract
Successful coiled tubing (CT) descaling interventions require control of several key aspects, including fluid leakoff into the formation, proper surface solids handling, and controlled hydrogen sulfide (H2S) release at the surface. Successful treatment control is achieved by monitoring the surface and downhole parameters. The recently introduced pressure and fluid management system, crosslinked foam-based fluid, and a fluid mixing system for CT descaling treatments pose challenges that require enhancements to these elements for successful treatment.
The pressure and fluid management system was enhanced to include a new high-rate mud/gas separator to 1) increase gas/fluid separation capacity and avoid foam flowing to flare, 2) rig up the flare line with inclination to allow all water to be drained and prevent formation gas flowing to flare lines, and 3) increase retention time for better foam breaking and material settling. A liquid flowmeter was also added to improve influx and leakoff control by monitoring the volume of liquid injected and matching the volume of liquid returned on surface in addition to the level gauges on the return tanks of the pressure and fluid management system. The foamed-based fluid breaking system and H2S presence in returns were mitigated by removing crosslinker and introducing an H2S scavenger on returns whereas foam breaking was enhanced by additional breaker injection points on returns. Fluid mixing capabilities were enhanced by the introduction of an on-the-fly continuous mixing system that sped up and simplified the mixing process.
The mud/gas separator efficiently separated the gas from liquid, leading the gas to be burnt at flare and the liquid to be processed in the pressure and fluid management system. It further helped in preventing the liquid flowing to flare, which lessened the risk of flare shutdown and H2S ventilation.
The on-the-fly continuous mixing system provided a faster and more-efficient mixing process as an alternate to batch mixing. These system-controlled metering, mixing, and monitoring capabilities significantly reduced the crew and equipment footprint, leading to minimizing the health, safety, and environment (HSE) concerns and cost savings.
The fluid flowmeter allowed efficient choke and bottom-hole pressure control. Fluid flowmeter readings helped in choke and bottom-hole pressure reading adjustments based on amount of fluids pumped and matching the same amount of fluids returned at the surface. It prevented the fluid leakoff into the formation or influx of gas into the wellbore.
Additionally, this new process created better control of downhole differential pressure during the scale cleanup and transportation. This project integrated different technologies and techniques that can be utilized for descaling treatment enhancements. The recent enhancements to the CT descaling operation resulted in greater efficiency, cost savings, reduced formation damage, and safe operations.
Offshore CRI Well Performance Diagnostics and Fractured Domain Mapping Using Injection Data Analytics and Hydraulic Fracturing Simulation, Verified Through 4D Seismic and Wireline Logging
Authors: Marketz Franz , Brown David , Alyabiev Roman , Khudorozhkov Pavel , Sychov Oleg 
Published: September 2021

Abstract
The cuttings re-injection (CRI) well in the Astokh area of Piltun-Astokhskoye field offshore Sakhalin Russia is one of the longest operating drilling waste disposal wells in the oil and gas industry worldwide. The Astokh area has been developed as a waterflood and is operated by Sakhalin Energy, a joint venture between Gazprom, Shell, Mitsui, and Mitsubishi. The Astokh CRI well has been utilized for waste injection for over 16 years. About 300,000 m3 of waste has been disposed into the main injection zone of the CRI well. Monitoring and modelling the CRI process to understand the evolution of the disposal domain is paramount for safeguarding further disposal operations.
The disposal domain can be described as a complex system of multiple hydraulic and natural fractures due to injection under fracturing conditions. CRI domain evaluation includes analysis of historical injection pressures to identify the reasons of continuous injection pressure increase with increasing cumulative waste volumes disposed, to confirm domain containment, and to predict remaining domain capacity. Transient pressure analysis has revealed that the fracture closure pressure, driven by pore pressure increase and the accumulation of injected solid-phase waste, is the key parameter affecting injection pressures. Injection intensity, periods of shut-in, large overflushes, and solids-free liquids injections with corresponding solids and stresses redistribution are the other factors that affecting the pressure trends. CRI domain mapping was carried out with history-matched time-lapse 3D hydraulic fracture models. Injection pressure history matching results reveal the fracture geometry evolution during well life. The distribution of the injected liquid phase in the sand layers was modeled with a 3D dynamic reservoir sector model, matched with injection pressures and with formation pressure data in two offset wells, located at a distance of 1 and 2 kilometers, respectively. A matched model was then used to assure fracture containment for future waste disposal and to estimate remaining domain capacity.
High-precision temperature and spectral noise logs were acquired in seawater injection and shut-in modes. The log-derived fracture height confirmed the domain size predicted by the matched model. 4D seismic data processing revealed that dimensions of Geomechanically Altered Rock Volume (GARV) were also in the same range as predicted by the model p.
The integration of CRI domain evaluation with matched 3D hydraulic fracture models, well logs and 4D seismic demonstrated that injection pressure data collected during every injection cycle may be sufficient to characterize disposal domain evolution and to estimate domain capacity.
Quantification of Temperature-Dependent Sorption Kinetics in Shale Gas Reservoirs: Experiment and Theory
Authors: Yang Yun , Liu Shimin 
Published: September 2021

Abstract
A critical component of natural gas in organic-rich shales is adsorbed gas within organic matter. Quantification of adsorbed gas is essential for reliable estimates of gas-in-place in shale reservoirs. However, conventional high-pressure adsorption measurements for coal on the volumetric method are prone to error when applied to characterize sorption kinetics in shale-gas systems due to limited adsorption capacity and finer pores of shale matrix. An innovated laboratory apparatus and measurement procedures have been developed for accurate determination of the relatively small amount of adsorbed gas in the Marcellus shale sample.
The custom-built volumetric apparatus is a differential unit composed of two identical single-sided units (one blank and one adsorption side) connected with a differential pressure transducer. The scale of the differential pressure transducer is ± 50 psi, a hundred-fold smaller than the absolute pressure transducer measuring to 5000 psi, leading to a significant increase in the accuracy of adsorption measurement. Methane adsorption isotherms on Marcellus shale are measured at 303, 313, 323 and 333 K with pressure up to 3000 psi. A fugacity-based Dubinin-Astakhov (D-A) isotherm is implemented to correct for the non-ideality and predict the temperature-dependence of supercritical gas sorption.
The Marcellus shale studied displays generally linear correlations between adsorption capacity and pressure over the range of temperature and pressure investigated, indicating the presence of a solute gas component. It is noted that the condensed phase gas storage exists as the adsorbed gas on shale surface and dissolved gas in kerogen, where the solute gas amount is proportional to the partial pressure of that gas above the solution. To our best understanding, it is the first time to observe the contribution of dissolved gas to total gas storage. With adsorption potential being modeled by a temperature dependence expression, the D-A isotherm can successfully describe supercritical gas sorption for shale at multiple temperatures. Adsorption capacity remarkably decreases with temperature attributed to the isosteric heat of adsorption. Lastly, the wide applicability of the proposed fugacity-based D-A model is also tested for literature adsorption data on Woodford, Barnett, and Devonian shale. Overall, the fugacity-based D-A isotherm provides precise representations of the temperature-dependent gas adsorption on shales investigated in this work. The application of the proposed adsorption model allows predicting adsorption data at multiple temperatures based on the adsorption data collected at a single temperature. This study lays the foundation for accurate evaluation of gas storage in shale.
Measurements During Drilling Through an Innovative Microchip Technology to Determine Accurate Wellbore Properties for Efficient Drilling Operations
Authors: Zhu Zuyang , Zhao Jinhai , Mulunjkar Amol , Rached Rached , Gramajo Eduardo , Li Fengbo , Wang Zhifa , Shi Zhaorui , Zhang Wei , Zhao Weishu 
Published: September 2021

Abstract
The measurement of the drilling parameters such as temperature and pressure helps mitigate drilling-related issues and optimize drilling operations on a cost-effective basis. Multiple technologies can measure these parameters; however, the current tools suffer from low bandwidth, associated high cost, and limited measurement locations near the drill bit.
This reduced accuracy and transmission rate while drilling can be improved using intelligent microchip tracers and micro-memory balls. These tools can measure the temperature and pressure across an entire wellbore. The proposed tracers include a microprocessor-based circuit board equipped with sensors, a communication antenna, and a rechargeable battery, all protected from the harsh downhole environment through a robust composite material.
The advanced microchip tracers and micro-memory ball technologies were tested in the field and provided innovative measurement platforms. The field tests were conducted in various environments, including oil and gas wells, deviated wells, multiple hole sizes, varied fluid densities, and different BHA (Bottom Hole Assembly) geometries. During the operation procedures, the tracers travel in the drilling strings through the drill bit and return to the surface across the annulus. The data is then exported from the tracers for a quasi-real-time analysis. The results showed high success rates, four out of six microchips were successfully retrieved, and the data was made available for immediate analysis.
This paper explains the challenges faced during the logging and interpretation of the data needed to define the wellbore characteristics for efficient drilling processes. The developed time-stepping algorithm correlates the measurement timestamp with the calculated depth. Lastly, the report summarizes the highlights of the tracers in terms of density, release mechanism, and collection method.
Stress Path Analysis of the Depleted Middle Miocene Clastic Reservoirs in the Badri Field, Gulf of Suez Rift Basin, Egypt
Authors: Radwan Ahmed E. , Sen Souvik 
Published: September 2021

Abstract
The purpose of this study is to evaluate the reservoir geomechanics and stress path values of the depleted Miocene sandstone reservoirs of the Badri field, Gulf of Suez Basin, in order to understand the production-induced normal faulting potential in these depleted reservoirs. We interpreted the magnitudes of pore pressure (PP), vertical stress (Sv), and minimum horizontal stress (Shmin) of the syn-rift and post-rift sedimentary sequences encountered in the studied field, as well as we validated the geomechanical characteristics with subsurface measurements (i.e. leak-off test (LOT), and modular dynamic tests) (MDT). Stress path (ΔPP/ΔShmin) was modeled considering a pore pressure-horizontal stress coupling in an uniaxial compaction environment. Due to prolonged production, The Middle Miocene Hammam Faraun (HF) and Kareem reservoirs have been depleted by 950-1000 PSI and 1070-1200 PSI, respectively, with current 0.27-0.30 PSI/feet PP gradients as interpreted from initial and latest downhole measurements. Following the poroelastic approach, reduction in Shmin is assessed and reservoir stress paths values of 0.54 and 0.59 are inferred in the HF and Kareem sandstones, respectively. As a result, the current rate of depletion for both Miocene reservoirs indicates that reservoir conditions are stable in terms of production-induced normal faulting. Although future production years should be paid more attention. Accelerated depletion rate could have compelled the reservoirs stress path values to the critical level, resulting in depletion-induced reservoir instability. The operator could benefit from stress path analysis in future planning of infill well drilling and production rate optimization without causing reservoir damage or instability.
The Experience of Drilling TAML-3 Well with Mutistage Fracturing on the Low Permeability Deposits of the West Siberia
Authors: Brednev Philipp , Elesin Mikhail , Berezovskiy Yuri , Metelkin Denis , Volkov Georgy , Firsin Maksim , Mukminov Iskander 
Published: September 2021

Abstract
This article deals with the issues related to development of petroleum resources of Western Siberia and looks at one of the most promising development targets – reservoirs of the Achimov Formation. In particular, it discusses geological features of the Achimov rocks, and the difficulties faced by oil companies in development of the Achimov reservoirs due to their low economic viability if traditional approaches to well construction are applied. To make development of such reservoirs economical, new and non-trivial solutions need to be looked for. One of the most promising of them is considered to be multi-hole wells the construction of which allows oil companies to improve the Capex to cumulative production ratio. At the pre-FEED stage the project, geological, hydrodynamic and geomechanical models of the reservoir were built, the most efficient borehole parameters and trajectories were defined, and the optimal hydraulic frac design, number of stages and parameters were selected.
The article describes specifics of the work carried out when preparing for pilot tests of the technology, such as:requirements for defining the well profile and selecting the optimal lifting capacity of the drilling rig,selection of a suitable complexity level for the double-hole well design among those considered which meets the drilling requirements,performance of bench tests to confirm operability of the TAML-3 equipment.
Further, the article describes results of drilling, completing and commissioning the first double-hole well at the Vyngayakhskoye field, discusses the issues faced when using the completion equipment at the TAML-3 level, and the lessons learned from this project. It also presents results of putting the double-hole well on-stream and compares its production characteristics with those of single-hole horizontal wells drilled within the same well cluster.
The experience gained has shown that building the discussed type of wells is technically feasible, and there is a wide potential for improving efficiency of this work through respective organizational and technical measures.
The conclusion to this article describes Gazprom Neft long-term plans to build several new wells of this design, and the technology development options such as increasing the length of horizontal segments for both holes and using high-rate multi-stage hydraulic fracturing.
Application of Multiple Diagnostic Plots to Identify End of Linear Flow in Unconventional Reservoirs
Authors: Pratikno Helmi , Lee W. John , Torres Cesario K. 
Published: September 2021

Abstract
This paper presents a method to identify switch time from end of linear flow (telf) to transition or boundary-dominated flow (BDF) by utilizing multiple diagnostic plots including a Modified Fetkovich type curve (Eleiott et al. 2019). In this study, we analyzed publicly available production data to analyze transient linear flow behavior and boundary-dominated flow from multiple unconventional reservoirs.
This method applies a log-log plot of rate versus time combined with a log-log plot of rate versus material balance time (MBT). In addition to log-log plots, a specialized plot of rate versus square root of time is used to confirm telf. A plot of MBT versus actual time, t, is provided to convert material balance time to actual time, and vice versa. The Modified Fetkovich type curve is used to estimate decline parameters and reservoir properties. Applications of this method using monthly production data from Bakken and Permian Shale areas are presented in this work.
Utilizing public data, our comprehensive review of approximately 800 multi-staged fractured horizontal wells (MFHW) from North American unconventional reservoirs found many of them exhibiting linear flow production characteristics. To identify end of linear flow, a log-log plot of rate versus time alone is not sufficient, especially when a well is not operated in a consistent manner. This paper shows using additional diagnostic plots such as rate versus MBT and specialized plots can assist interpreters to better identify end of linear flow. With the end of linear flow determined for these wells, the interpreter can use the telf to forecast future production and estimate reservoir properties using the modified type curve.
These diagnostic plots can be added to existing production analysis tools so that engineers can analyze changes in flow regimes in a timely manner, have better understanding of how to forecast their wells, and reduce the uncertainty in estimated ultimate recoveries related to decline parameters.
Experience of Using Continuous Production Surveillance Techniques in Multilateral Wells
Authors: Husein Nadir , Upadhye Vishwajit , Novikov Igor Leonidovich , Drobot Albina Viktorovna , Bolshakov Viacheslav Valeryevich , Buyanov Anton Vitalyevich , Doronin Vladimir Alekseevich 
Published: September 2021

Abstract
This paper deals with the case of using the production surveillance inflow tracer-based method in one of multi-lateral wells located in West Siberia.
Tracer systems were placed in the well during the well construction by horizontal side tracking, and multi-stage hydraulic fracturing (MSHF) was performed, with the parent borehole remaining in operation. This technology allows developing the reservoir drainage area with a lateral hole and bringing the oil reserves remaining in the parent borehole into production, which results in an increased well productivity and improved oil recovery rate.
Tracer systems are placed into the parent borehole within a downhole sub installed into the well completion. Polymer-coated proppant pack was injected during multi-stage hydraulic fracturing to deliver the tracers to the side track lateral.
Dynamic production profiling was done to aid into more efficient development of complex and heterogeneous reservoirs and improve of the productive reservoir sweep ratio during the construction of multilateral wells, which enabled us to address several key problems:
Providing tools for waterflood diagnostics in multilateral wells and finding an easy water shut- off method for a certain interval Assessing the efficiency of multi-stage hydraulic fracturing and elaborating the optimal treatment design Selecting the optimal mode of the multilateral well operation to prevent premature flooding in one or more laterals Evaluating whether well construction was performed efficiently, and a higher production was achieved by side tracking.
Currently, the proposed first-of-its-kind solution enables the operator to obtain a set of data that can help not only significantly improve the wells productivity and increase the oil recovery rate, but also lead to a considerable economic savings in capital expenditure.
Cost-Effective Chemical EOR for Heterogenous Carbonate Reservoirs Using a Ketone-Surfactant System
Authors: Alghunaim Etaf , Uzun Ozan , Kazemi Hossein , Sarg J. Frederick 
Published: September 2021

Abstract
The complexity, high cost, and potential environmental concerns of chemical enhanced oil recovery (EOR) methods have diminished their field applications considerably. However, considering the significant incremental oil recoveries that can be obtained from these methods encourage researchers to explore ways to reduce both complexity, cost, and environmental concerns of such systems. This is especially important in carbonate formations, where after waterflooding, much of the oil remains trapped in complex reservoir pores—especially if the reservoir contains an interconnected fracture network of flow channels within the bulk rock matrix.
In this paper, we present an experimental assessment of several simple chemical EOR waterflooding systems comprising of small concentrations of a low cost, low molecular weight ketone and a non-ionic surfactant in association with low-salinity brine. The experiments were conducted in carbonate cores from a Permian Basin San Andres Formation. Four different oil displacement scenarios were investigated using San Andres carbonate cores from the Central Vacuum Field in New Mexico. This included 1) low-salinity brine, 2) low-salinity brine with a surfactant, 3) low-salinity brine with a ketone, and 4) low-salinity brine with a combined ketone-surfactant system. Static imbibition experiments were conducted using a spontaneous imbibition apparatus in addition to the use of a high-speed centrifuge to saturate the cores to irreducible brine saturation.
Adding a 1% concentration of 3-pentanone and a 1% non-ionic surfactant to a low-salinity brine yielded oil recoveries of 44% from the 3-pentanone system, compared to 11.4% from low-salinity brine only. The oil recovery is enhanced by a single mechanism or synergy of several mechanisms that includes interfacial tension (IFT) reduction by surfactant, capillary imbibition, favorable wettability alteration by ketone, and osmotic low-salinity brine imbibition. The IFT decreased to 1.79 mN/m upon addition of non-ionic surfactant to low-salinity brine, and it reduced to 2.96 mN/m in a mixture of 3-pentanone and non-ionic surfactant in low-salinity brine. Furthermore, ketone improved the core wettability by reducing the contact angle to 43.9° from 50.7° in the low-salinity brine experiment. In addition, the low-salinity brine systems caused mineral dissolution, which created an alkali environment confirmed by an increase in the brine pH. We believe the increase in pH increased the hydrophilic character of the pores; thus, increasing oil recovery.