bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geophysical Aspects of Reservoir Characterization of Tight Gas Play in the Dnieper-Donets Basin
Authors: Valiakhmetov Rustem , Murineddu Andrea , Zhiyenkulov Murat , Maliar Viktor , Bugriy Viktor , Kashuba Grigori , Loktiev Valentyn , Kuzmenko Pavlo , Gerecitano Francesco , Romi Alessandro , D'Aguanno Carlo 
Published: November 2021

Abstract
The objective of this work is to describe a comprehensive approach integrating seismic data processing and sets of wireline logs for reservoir characterization of one of the tight gas plays of the Dnieper-Donets basin.
This paper intends to discuss a case study from seismic data processing, integrating seismic attributes with formation properties from logs in a geocellular model for sweet spot selection and risk analysis.
The workflow during the project included the following steps.
Seismic data 3D processing, including 5D interpolation and PSTM migration. Interpretation of limited log data from 4 exploration and appraisal wells. Seismic interpretation and inversion. Building a static model of the field. Recommendations for drilling locations. Evaluation of the drilled well to verify input parameters of the initial model.
The static model integrated all available subsurface data and used inverted seismic attributes calibrated to the available logs to constrain the property modelling. Then various deterministic and stochastic approaches were used for facies modeling and estimation of gas-in-place volume.
Integrating all the available data provides insights for better understating the reservoir distribution and provided recommendations for drilling locations. Based on the combination of the geocellular model, seismic attributes and seismic inversion results, the operator drilled an exploration well. The modern set of petrophysical logs acquired in the recently drilled well enforced prior knowledge and delivered a robust picture of the tight gas reservoir.
The results from the drilled well matched predicted formation properties very closely, which added confidence in the technical approach applied in this study and similar studies that followed later.
It is the fork in the road moment for the Dnieper-Donetsk basin with huge tight gas potential in the region that inspires for exploration of other prospects and plays.
A synergy of analytical methods with a combination of seismic processing, geomodeling, and reservoir characterization approaches allowed accurate selection of the drilling targets with minimum risk of "dry hole" that has been vindicated by successful drilling outcome in a new exploration well.
Successful Implementation of Managed Pressure Drilling and Managed Pressure Cementing Techniques in Fractured Carbonate Formation Prone to Total Lost Circulation in Far North Region
Authors: Kazakbayeva Zhanna , Kaidarov Almas , Magda Andrey , Aliyev Fuad , Patil Harshad , Dietrich Earl , Cook Iain 
Published: November 2021

Abstract
Drilling reservoir section in the oilfield located in Far North region is challenged with high risks of mud losses ranging from relatively minor losses to severe lost circulation. Numerous attempts to cure losses with traditional methods have been inefficient and unsuccessful. This paper describes implementation of Managed Pressure Drilling (MPD) and Managed Pressure Cementing (MPC) techniques to drill 6-1/8″ hole section, run and cement 5″ liner managing bottomhole pressure and overcoming wellbore construction challenges.
Application of MPD technique enabled drilling 6-1/8″ hole section with statically underbalanced mud holding constant bottom hole pressure both in static and dynamic conditions. The drilling window uncertainty made it difficult to plan for the correct mud weight (MW) to drill the section. The MW and MPD design were chosen after risk assessment and based on the decisions from drilling operator. Coriolis flowmeter proved to be essential in deciphering minor losses and allowed quick response to changing conditions. Upon reaching target depth, the well was displaced to heavier mud in MPD mode prior to open hole logging and MPC.
MPD techniques allowed the client to drill thru fractured formation without losses or gains in just a couple of days as compared to the months of drilling time the wells usually took to mitigate wellbore problems, such as total losses, kicks, differential sticking, etc. This job helped the client to save time and reduce well construction costs while optimizing drilling performance.
Conventional cementing was not feasible in previous wells because of risks of losses, which were eliminated with MPC technique: bottomhole pressure (BHP) was kept below expected loss zones that provided necessary height of cement and a good barrier required to complete and produce the well. Successful zonal isolation applying MPC technique was confirmed by cement bond log and casing integrity test.
Throughout the project, real-time data transmission was available to the client and engineering support team in town. This provided pro-active monitoring and real-time process optimization in response to wellbore changes.
MPD techniques helped the client to drill the well in record time with the lowest possible mud weight consequently reducing mud requirements. The MPD system allowed obtaining pertinent reservoir data, such as pore pressure and fracture pressure gradients in uncertain geological conditions.
Manuscript Title: Unlocking New/Missed Reservoir Zones at Shallow Depth Based on Integrating Post-Hydraulic Fracture Performance with Reservoir, Petrophysics, and Geology Data
Authors: Nashaat Michael , Kolivand Hassan , Zhiyenkulov Murat , Seilov Yerlan , Ghorayeb Kassem , Shah Abdur Rahman , Madatov Roman , Grytsai Svetlana , Filatov Viacheslav 
Published: November 2021

Abstract
Skhidno-Poltavske Field is a Ukrainian gas field producing mostly from commingled wells. These commingled wells have no information about the production split and the pressure data measured for each formation separately. This was one of the main challenges to study the field and understand the potential of each individual formation. Many wells were hydraulically fractured (HF) and showed a wide range of production and pressure performance after the stimulation.
Six of these HF wells showed atypical pressure and production behavior after the HF compared to the rest of the wells. The main challenge in the reservoir simulation study was to understand whether these HFs reached isolated lateral segments of the same producing zones or accessed other reservoir zones by/due to vertical propagation of the hydraulic fracture plane.
Understanding the pressure and production performance of these wells and comparing them to the other wells was the key to revealing their behavior. This was integrated with the petrophysical data to understand the potential formations and the uncertainty range of their properties. The geomodeling was the destination to translate these uncertainties into different realizations that were all dynamically tested to generate the most probable realization.
The integration between different domains resulted in unlocking an overlooked productive zone that was out of consideration. This increased the reserves of this field and extended its life. One of the study recommendations was to test and develop this formation through perforating the existing wells or drilling new wells targeting the overlooked productive zone.
A Novel Integrated Approach to 3D Modeling and History Matching of Gas Condensate Fields with Paucity of Geological and Production Data
Authors: Grytsai Denys , Shtefura Petro , Dodukh Vadym 
Published: November 2021

Abstract
A methodology has been developed that, in conditions of limited geological and production data, ensures the integration of petrophysical, geological, and hydrodynamic models as components of a permanent 3D model, establishing physical relationships between parameters that describe the entire system.
In the proposed method, the modelling is based on the results of the interpretation of continuous shale volume and porosity curves. Based on the analysis of core data, the multi-vector physical correlations with other parameters are made. To distinguish the reservoirs and non-reservoirs, the cut-off values of shale volume are defined; to exclude tight reservoirs with no filtration, the cut-off values of porosity are set. Using the Winland R35 method the radius of the pore throat is computed, allowing dividing the reservoirs into classes. For each class of reservoirs, the permeability vs porosity dependence is determined, and the Wright-Woody-Johnson method allows deriving equations for the bound water content. A system of configured workflows has been developed and allows automating re-modelling and simplifying its history matching.
This technique was successfully applied to several 3D models of gas condensate fields, which, with a significant drilling level on the areas and a long development history, are characterized by limited geological and production data. Workflows System together with the proposed approach allowed simplifying the history matching process by splitting it into several stages. At each stage, depending on the type of input data, various parameters were matched (production, reservoir and wellhead pressures, etc.). Due to cross-functional correlation of all components, the model has significantly reduced the uncertainty parameters and allowed a detailed history matching of the development history for the entire well stock. The results obtained were tested by several geological and technological measures, including drilling new wells, and showed high convergence with the forecast indicators.
The proposed approach to modelling and history matching in conditions of limited geological and production data allows:
– ensuring integration and correlation of petrophysical, geological, and hydrodynamic models as components of a permanent 3D model; – automating and simplifying the modelling, history matching, and updating a model; – improving the quality of parameters’ matching results.
Modeling the Effects of Various Liquid Droplet Sizes in Acoustic Deliquification Techniques
Authors: Al Munif Eiman , Alrashed Ahmed , Karatayev Kanat , Miskimins Jennifer , Fan Yilin 
Published: November 2021

Abstract
Liquid loading is a major challenge in natural gas wells. Enhancing the production in liquid loading natural gas wells using an acoustic liquid atomizer tool is proposed as a possible artificial lift method. The effect of different droplet sizes on the transport efficiency and the performance of the proposed technique during production are studied using Computational Fluid Dynamics (CFD) simulation. Also, the liquid behavior and fluid dynamics after applying the atomization mechanism are reviewed.
In the model, the tool is placed axially in the middle of the gas/air flowing wellbore. To reduce computational time, the tool and pipe are cut symmetrically. The pipe diameter is 4 in, and the four injectors diameters are each 0.04 in. The orientation of the injectors is set to 90° with the sprayers facing sideways, while water liquid droplets are injected from the tool surface into the air flow at angles from 45° to the flow direction. Unstructured hybrid mesh is used to allow the cells to assemble freely within the complex geometry. Sensitivity tests were conducted with droplet sizes ranging between 30-300 µm.
The CFD results showed that water liquid droplets of size 30 µm followed the pathway along the tool surface due to the low mass of the droplets and high air velocity. This phenomenon is called wall impingement and occurs where the droplets are very small and clustering on the wall. The 200 and 300 µm water liquid droplets kept their inertial high chaotic movements in all directions within the computational fluid domain due to the increased weight of the droplets. These larger sized droplets withstand the backpressure from high turbulent air velocity and tend to keep their inertial turbulent movement.
This research presents a set of CFD results to further evaluate acoustic atomization as a possible artificial lift technique. This technique has never been commercially applied in the oil and gas industry, and continued evaluation of such methods is a vital addition to the industry as it brings the potential for new lower cost artificial lift technologies. If completely developed, this technique can bring a cost-effective solution compared to conventional artificial lift methods.
The Results of an Integrated Study of Unconventional Reservoirs and a First Attempt at their Development
Authors: Kudryashov Alexey 
Published: November 2021

Abstract
Rechitsa multi-play oilfield is located within the Rechitsko-Vishanskaya subregional area of local uplifts of the Rechitsko-Vishanskaya tectonic stage of the Northern structural zone of the Pripyat Trough in the Republic of Belarus. Since 2014, Production Association Belorusneft has been conducting integrated research to study oil bearing capacity of sediments within rock Units I-III, which were previously considered to have no potential. Since then, the lithological and petrophysical, pyrolytic, and geomechanical features of the structure of these sediments have been studied. The research has confirmed the initial hypothesis that the studied sediments are unconventional reservoirs with source-rock genesis and contain hydrocarbons both of their own genesis and those which migrated from other rocks. The results of drilling and completion of horizontal exploration wells with multi-stage hydraulic fracturing confirmed the potential for obtaining commercial oil from the sediments of the unconventional reservoirs. At the same time, there were doubts about the optimal placement of the horizontal wells, the choice of completion strategy, and if the well performance lived up to the actual maximum potential of these sediments.
The paper sums up the main results of implementing an integrated program for studying unconventional reservoirs of the Rechitsa oilfield, as well as of drilling and operating production wells to date.
Basins Analysis and Petroleum Systems Modeling of Western Black Sea, Ukrainian Sector
Authors: Karpenko Ivan , Ischenko Ihor , Nikolenko Olha , Rodrigues Felipe , Levonyuk Serhii , Glon Vitalii , Wygrala Bjorn , Privalov Vitalii 
Published: November 2021

Abstract
The Ukrainian sector of the Western Black Sea (WBS) is one of the last remaining exploration frontiers in Europe. This area, which includes shelf to deepwater environments, is underexplored with no drilling of targets in water depths exceeding 100 meters. That is why, the Ukrainian sector of the WBS is attractive for exploration, especially in the context of new play types and targets such as biogenic gas. These hydrocarbon formations have been proven by neighboring Romania and Turkey in the areas adjacent to Ukrainian waters.
Therefore, a rigorous Basin Analysis program has been initiated to assess the petroleum systems and play risks in the entire Ukrainian sector of the WBS. The goals of this program are: 1) to establish a regional geoscience foundation following best industrial practices in exploration; 2) to enable establishing more accurate risking and ranking procedures for an exploration portfolio and 3) to provide critical support for the analysis of a new generation of seismic data that is currently being acquired. In this paper the initial scope of work is presented.
A Comprehensive Machine Learning Approach for Quantitatively Analyzing Development Performance and Optimization for a Heterogeneous Carbonate Reservoir in Middle East
Authors: Huang Ruijie , Wei Chenji , Wang Baohua , Li Baozhu , Yang Jian , Wu Suwei , Xiong Lihui , Li Zhengzhong , Lou Yuankeli , Gao Yan , Liu Shuangshuang , Sudakov Vlad 
Published: November 2021

Abstract
Compared with conventional reservoir, the development efficiency of the carbonate reservoir is lower, because of the strong heterogeneity and complicated reservoir structure. How to accurately and quantitatively analyze development performance is critical to understand challenges faced, and to propose optimization plans to improve recovery. In the study, we develop a workflow to evaluate similarities and difference of well performance based on Machine Learning methods. A comprehensive Machine Learning evaluation approach for well performance is established by utilizing Principal Component Analysis (PCA) in combination with K-Means clustering. The multidimensional dataset used for analysis consists of over 15 years dynamic surveillance data of producers and static geology parameters of formation, such as oil/water/gas production, GOR, water cut (WC), porosity, permeability, thickness, and depth. This approach divides multidimensional data into several clusters by PCA and K-Means, and quantitatively evaluate the well performance based on clustering results. The approach is successfully developed to visualize (dis)similarities among dynamic and static data of heterogeneous carbonate reservoir, the optimal number of clusters of 27-dimension data is 4. This method provides a systematic framework for visually and quantitatively analyzing and evaluating the development performance of production wells. Reservoir engineers can efficiently propose targeted optimization measures based on the analysis results.
This paper offers a reference case for well performance clustering and quantitative analysis and proposing optimization plans that will help engineers make better decision in similar situation.
Specifics of Implemented Development System of Shtormove Field Black Sea Offshore
Authors: Bahniuk Mykhailo Mykytovych , Vladyka Vitaliy Mykolaiovych , Hotsynets Oleh Stepanovych , Dmyshko Oleksandra Olehivna , Dorokhov Maksym Volodymyrovych , Bodlak Vasyl Petrovych , Kozak Lesia Mykhailivna 
Published: November 2021

Abstract
The development system of the main hydrocarbon deposit of the Shtormove field was designed taking into account the change in reservoir rock properties in horizontal and vertical sections of the gas-saturated interval. Based on the results of core analyses and interpretation of logging data from exploration and appraisal wells, maximum porosity values were assigned to the top part of the deposit, with lower porosity values assigned closer to the gas-water contact area. The analyzed thin sections demonstrated vertical and subvertical fractures, as well as multiple pores and dissolution vugs. Most of the fractures occur in the top part of the gas-condensate deposit. Natural fractures in the rocks of the productive interval were confirmed by well testing using a steady flow analysis.
Taking into account the determined reservoir properties’ distribution pattern in the gas-condensate deposit II, the wells were drilled in the top part of the deposit from a fixed offshore platform during the pilot development period. During this period, the estimated recoverable gas reserves’ values matched the values obtained using the volumetric estimation method. In the following years, in order to increase the gas recovery rate, the infilling production wells were drilled in the top part of the deposit. Based on the analysis of the development, it was determined that the addition of new wells had little effect on the performance of existing ones. As a result, attributable to infill drilling in the top part of the deposit, the annual gas production increased. Given the similarity of the geological model and distribution of reservoir properties, the implemented development system of the Shtormove field should be recommended for new development targets.
List of Analogues for Highly Productive Rocks Around Salt Domes
Authors: Loktyev Valentyn , Zharkeshov Sanzhar , Hotsynets Oleh , Davydenko Oleksandr , Machuzhak Mikhailo , Pavlo Kuzmenko , Repryntsev Vitalii 
Published: November 2021

Abstract
In the Dnipro-Donets depression, the Devonian salt during Carboniferous time became movable and created salt domes in the Permian, moving to the sea bottom and flowing therewith, forming bodies visible today as salt canopies and overhangs. These features are clear pieces of evidence of salt exposure on the surface, especially considering belts of reservoirs around salt domes. These reservoirs can be extremely prolific in some wells.
Previous exploration targeting such deposits was driven mainly by drilling wells within the areas of known deep fields such as Medvedivske, Zakhidno-Khrestyschenske and others in the central part of the DDB. These reservoirs are composed of poorly sorted coarse material of wide variety of rocks including sandstones, carbonates, dolomites, igneous rocks of deep (granites), and shallow (diabases) formations. Currently, with the availability of 3D seismic surveys, these deposits become visible as bright spots and flat spots. Although it is not a 100% indicator due to fact that shallow salt canopies and lithology changes of rocks around salt domes may also interpret seismic reflections.
It is good to mention that the Permian is an aridic environment with gradually losing water influx to the basin from base to top within the thickness of more than 1-2 kilometers. It could be utilized as boundary analogues to cover most of the possible intermediate scenarios in three areas. The first analogue is the outcropped salt dome in Solotvyno village in Carpathian mountains in western Ukraine close to the Romania border. This salt dome is an important example of showing the current deposition of transported coarse material from depth around salt domes. The second one is salt domes exposed as mountains of the Oman desert where it is possible to follow the material path approaching the salt uplift. And the third example is the Death Valley in Arizona, USA. The valley is an example of fans mostly deposited by gravity rather than permanent water flows. It good to mention that there are more examples that could be treated as direct analogues (the Zagros mountains in Iran) but they are not easily accessible for field trips if needed.
For recognizing real targets vs artifacts, applying the knowledge of current deposition examples around the world would help dramatically (Western Ukraine, Oman, Death Valley in Arizona).