bluuebunny/crossref_metadata_2025 huggingface dataset:
Expand Excellence: Business Intelligence Tools for Drilling Data Analysis as Enhanced Efficiency Approach
Authors: Rakhmangulov Farit , Garipov Andrey , Chertenkov Mikhail
Published: October 2021

The business intelligence tools allow you to work with databases containing historical drilling records. This gives a possibility to collect data into a single visualized shell, to see patterns, and, most importantly, to identify the main issues. A database among Yamal region projects was taken as an example. This process automation allows you to reduce the time for collecting information and makes it possible to conduct a more detailed and thoughtful analysis of project indicators. In turn, this results in making quick and effective decisions.

At the initial stage, historical drilling data over three years was analyzed, namely information on more than 800 drilling runs. A model was formed from various sources in reliance on the database, and a visual working dashboard of the project was compiled. The dashboard allowed us to recognize the main issues that were plain to see. Awareness of plain-to-see issues gives the possibility to find out what information needs to be added to the data model in order to perform more thoughtful analysis. Collecting all the data in one place is not enough. In order to bring the data together, they were collated and visualized in the most explicit way.

The bulk data collected in a single model allowed us to see the whole picture of what was happening on the project and to concentrate on solving the root problem. Major issues resulted in equipment failures due to vibrations in the horizontal section. A more detailed vibration analysis showed that the bit was the main driver of vibrations. Hence, the data on rock strength and bottom hole assembly (BHA) vibrations were added to the model for further analysis. However, the complete package of data does not guarantee success. It becomes problematic to see the patterns in some situations, since analogous wells are not always available. While business intelligence tools make it easy to manage filters and find analogy, that is only fair if you have enough offset data. Based on the analysis, the most efficient bit designs were selected and proposed. The updated range of bits allowed to increase ROP in the horizontal section and reduced failures due to vibrations, so the well construction cycle was shortened.

These tools are accessible for technicians, which means there is no need-to-know programming languages. Suggested approach allows to accelerate decision-making and identification of key issues. In addition, existing tools give the possibility to monitor key performance indicators continuously within a single project as well as throughout the country. In contrast to the well-known program with tables, the main advantage is the automatic update of the already built data model. This fact speeds up the analytical process and report generation by times.
Well Performance Monitoring Using Management by Exception Rules and Alerts
Authors: Nadirov Maruan , Sadyrbakiyev Renat , Skopich Anton
Published: October 2021

Wells in Tengiz and Korolev oil fields are equipped with data transmitting devices, which provide real-time process data used by Production engineers for continuous production monitoring and identification of unusual process conditions. Monitoring and analysis of each well performance becomes a tedious process with growing well inventory. Up until recently, real-time data from wellsite transmitters was not used to its full potential to simplify and automate well performance analysis. To improve the quality of daily well performance monitoring and detection of abnormal process conditions, sets of data rules have been developed to create alerts and screens with real-time process data managed by exception. These alerts and screens help to identify malfunctioning equipment and changes in operating conditions. Timely evaluation of critical conditions helps to proactively prepare a mitigation plan and prevent unscheduled well shutdowns.

Data management by exception allows automatic filtering of big data sets and draws attention only to wells with deviations from the stable operating regime. Detailed review of highlighted well conditions helps to differentiate between malfunctioning equipment and actual changes in operating conditions. Fast identification of the issues allows taking preventative actions to maintain process stability of each producing well. Implementation of these tools significantly reduced number of unscheduled well shutdowns due to leaks in Surface Controlled Subsurface Safety Valve (SCSSV) hydraulic system and pneumatic valves control system. The screens also help to identify malfunctioning equipment including pressure and temperature gauges, pressure downhole gauges (PDHGs) and multiphase flow meters (MPFMs), as well as flow assurance issues such as hydrate formation.

Developed data rules can be useful for any field equipped with data transmitting devices. This paper aims to share the best practices of using real-time operational data analytics to identify malfunctioning equipment, changing operating conditions and other process related issues to maintain stable production process.
Mitigating Well Construction Challenges of a Caspian Deepwater Exploratory Well: A Cementing Perspective
Authors: Kurawle Irfan , Dieker Ansgar , Soltero Adriana , Nafikova Svetlana
Published: October 2021

BP returned to Caspian deepwater exploratory drilling in 2019. The exploration well was drilled on the Shafag-Asiman structure in water depths greater than 2,000 ft. Well challenges included high shallow water flow (SWF) risk with multiple re-spuds on the nearest offset, lost circulation due to complex wellbore geometry combined with a narrow pore and fracture gradient window, and uncertainty in pore pressure prediction in abnormally pressured formations with a new depositional model. In addition, a well total depth more than 23,000 ft, eight string casing design and bottom-hole pressures greater than 20,000 psi presented a truly modern-day challenge to well integrity. A six-month planning phase for the cementing basis of design concluded by delivering slurry designs capable of combating SWF, qualified by variable-speed rotational gel strength measurement. Engineered lost circulation with selective placement of wellbore strengthening materials in combination with cement and mechanical barriers to provide isolation and integrity for the life of the well. Exhaustive pilot testing to account for changes required a cement design based on pore pressure variation and comprehensive modeling for hydraulics, centralizer placement, and mud displacement. This was complemented by a custom centralizer testing process specifically designed to simulate forces exerted in wells with similar complexity. Long-term effects on cement were evaluated, not only for placement but also for future operations including pressure and temperature cycles during wellbore construction or abandonment.
Continuous Improvement in Well Delivery
Authors: Ismayilov Elshan , Jabbarov Farkhan , Cherukuri Apparao
Published: October 2021

The Bulla gas-condensate reservoir is located in the north-west side of Baku Archipelago, is one of the most complex high-pressure fields in the world, with close PPFG margins and reactive clay in the overburden. The objective of this paper is to share the experience of how the challenges in the overburden section are managed to achieve improvement in the well delivery, through the application of continuous learning approach and the use of new technologies.

The Bulla wells are highly complex wells in the region. The overburden shales are young sediments 250 to 1200 m to be drilled and cased off with 24" casing, this has significant challenges such as slow ROP, Bit Balling and tight hole due to the shale swelling. These challenges can lead to issues such as stuck pipe and lack of zonal isolation. To overcome the challenges and similar cases in well delivery, continuous improvement (CI) techniques and new technologies were evaluated and applied in the project.

The CI approach helped identify the issues in the delivery of the overburden and actions taken resulted in significant improvement in well delivery and reduced the risks. The issues were worked on, and most feasible solution was chosen. The improvement plan has been risk assessed for the challenges of handling large volumes, possible losses, spillage etc. and risk control actions are implemented. The next well was drilled with higher operational efficiency, cost optimization and better hole quality to achieve zonal isolation by proper placement of cement. Further improvements were planned for the next wells in the field, by extending under reaming range through the application of new technologies. For 18 5/8" casing, a hole size of 24" required, this was drilled using multiple trips due to tool limitations. By using the advanced drilling dynamics software, BHA along with the required under reamer identified tools and design the section was delivered in one run. The application of this approach will not only reduce the time and cost but will also will help to deliver a quality well bore.

The study provides an overview of how CI can be effectively implemented to achieve the overall improvement in the performance of the well delivery. Additionally, it gives insight on how new technologies in BHA design and reaming can improve the drilling performance.
Healthy Caspian Experience helps Boost Drilling Performance in Turkey's Onshore UGS Project
Authors: Akbarli Elchin , Mammadbayli Rufat
Published: October 2021

The company is executing an underground gas storage project at an unprecedented scale. The intent of this paper is to demonstrate the execution methodology and technologies that the company employed to achieve within set deadlines and deliver the work on time and under the given budget. This paper, therefore will focus on outlining all planning, design as well as drilling & completions strategies utilized by the operating company during the execution phase.

During Phase 2 of the project, the Drilling Contractor was engaged to deliver a total of 40 wells within a short period of time. These wells were planned to expand the total gas storage capacity at the Tuz Golu facility to ca. 5 bcm of natural gas stored in underground salt caverns. Tuz Golu wells are vertical with three (3) casing string wells. These land wells are big bore and commence from the installation of the 30″ conductor at a depth of 120m using a small 150-ton conductor rig.

Pre-installation of conductors significantly helped accelerate the project delivery schedule. Main drilling operations commenced in January 2020. Since the structure wasn't fully explored in spite of 2D seismic work and the first phase operations, a number of wells drilled encountered no salt leading to their abandonment. As a result, the total duration of the project was consequently extended. Re-Engineering and lessons learned during execution helped deliver a successful learning curve in both drilling and completion operations. The strategy of the company to drill a well in stages of top hole, main drilling and the completion using multiple rig operations was successful, bringing an overall well time from 55 at the beginning of the project to 20 days per well. Thorough planning and design of the wells allowed the company to deliver the projects with well integrity, full suitable for gas storage operations. As a result, the project was executed on time and well within the planned budget thus delivering an excellent value to the stakeholders and main client.

The Drilling Contractor has been proactive to employ this staged approach from the very beginning of the project. Irrespective of the delays the Drilling Contractor continued operations with the intermittent rig count of 4 to 8 rigs. A large scale operation demanded careful planning and continuous application of lessons learnt from the first phase which were successfully embedded and implemented.
Mud-Removal Efficiency Boost by Engineered Scrubbing Spacer in Cementing Operations at Caspian Sea
Authors: Bugrayev Amanmammet , Singh Ravindra Kumar , Nafikova Svetlana , Akhmetzianov Ilshat , Gurbanov Guvanch , Rovshenov Gadam , Mehtar Mohammed Arif
Published: October 2021

Long-term well integrity and zonal isolation are the ultimate objectives for cementing in the well construction process. Effective mud removal plays an essential role in obtaining competent zonal isolation and hence should not be overlooked and underestimated. The negative consequences of poor mud removal can lead to microannulus, channeling, or gas migration, which might require costly time-consuming remediation.

The conventional approach of optimizing spacers based on chemical interactions with the mud layer does not always yield desired results and, thus, demanding further improvement. In this paper we discuss the approach taken to boost the mud removal efficiency by implementing an innovative engineered scrubbing spacer containing fibers in a challenging environment, resulting in notable improvement in long-term cement sheath integrity. The engineered scrubbing fibers were thoroughly tested in the laboratory to ensure spacer stability and efficiency.

The new spacer with an additional scrubbing capability was introduced to one of the major operators on the Caspian shelf and after successful implementation, it has now been used on more than 20 cementing operations. Scrubbing fibers concentration was optimized through thorough laboratory testing covering flowability, dispersibility, and mud removal efficiency; later, it was applied on most of the cement operations, including 4½-in. liners characterized by a very narrow annular gap across the hanger sections. Cement evaluation log results from those cementing operations demonstrated an improvement in mud removal efficiency, suggesting no issues associated with microannulus, channeling, or gas migration, thus confirming the effectiveness of the newly implemented engineered scrubbing spacer.

The typical challenges associated with meeting the zonal isolation requirement on one of the offshore fields of the Caspian shelf, and the success of the approach taken to overcome those challenges by implementing the new engineered scrubbing spacer are discussed. The comparison of cement bond evaluation log results of the jobs where conventional spacer systems were used vs. those where the spacer with scrubbing capability was used are also presented, demonstrating the clear difference and improvement.
Assurance of Long-Term Well Integrity in Highly Corrosive Downhole Environment
Authors: Khattak Mohammad Arif , Afrianto Agung Arya , Jain Bipin , Rashdi Sami , Khalifa Wahshi , Ferras AbdelKader , Balushi Humaid , Kendi Abdul Sallam Ibrahim , Obaidani Rashid
Published: October 2021

Portland cement is the most common cement used in oil and gas wells. However, when exposed to acid gases such as carbon dioxide (CO2) and hydrogen sulfide (H2S) under downhole wet conditions, it tends to degrade over a period of time. This paper describes the use of a proprietary novel CO2 and H2S resistant cement system to prevent degradation and provide assurance of long-term wellbore integrity.

The CO2-resistant cement was selected for use in one of the fields in Sultanate of Oman after a well reported over 7% CO2 gas production resulting in well integrity failure using conventional cements. The challenge intensified when the well design was modified by combining last two sections into one long horizontal section extending up to 1,600 m. The new proposed cement system was successfully laboratory- tested in a vigorous CO2 environment for an extended period under bottomhole conditions. Besides selecting the appropriate chemistry, proper placement supported by advanced cement job simulation software is critical for achieving long-term zonal isolation.

The well design called for a slim hole with 1,600 m of 4 ½-in liner in a 6-in horizontal section where equivalent circulating density (ECD) management was a major challenge. An advanced simulation software was used to optimize volumes, rheologies, pumping rates, and ECDs to achieve the desired top of cement. The study also considered a detailed torque and drag analysis in the horizontal section, and fit- for-purpose rotating-type centralizers were used to help achieve proper cement coverage.

To date, this cement system has been pumped in 32 wells, including 24 with 6-in slimhole horizontal sections with no reported failures.

The paper emphasizes the qualification and successful implementation of fit-for-purpose design of CO2- and H2S-resistant cement as well as optimized execution and placement procedures to achieve long-term zonal isolation and well integrity in a complex slimhole horizontal well design.
Mitigating Lost Circulation Across Permeable Formations of the Gunashli Field in the Caspian Sea with a New Tailored Spacer System
Authors: Farrow Tom , Gadimov Nurlan , Agapiou Kyriacos , Safarov Mukhtar
Published: October 2021

Cementing operations seek to minimize non-productive time (NPT) as part of the broad effort to optimize costs. A commonly encountered event that contributes to NPT is lost circulation. Lost circulation may often be associated, and treated, during drilling operations, but can occur during cementing practices, e.g. while running casing in the wellbore and/or circulating cement and treatment fluids. When fluids are lost to the formation and not appropriately cured, cementing objectives may not be met and, ultimately, zonal isolation can be compromised. Additional costs may be incurred to remediate the well construction and achieve a dependable barrier. It is, therefore, of great interest to develop and implement solutions which can facilitate the prevention and treatment of lost circulation.

Described herein is the evaluation and use of a new tailored spacer system (TSS) engineered to effectively prevent lost circulation and maintain wellbore stability. The TSS was designed for use in cementing shallow water Caspian Sea wells with permeable formations and a history of losses. The spacer was subjected to conventional spacer tests and simulations including rheological measurements, compatibility assessments and fluid modeling to ensure job requirements would be met. Loss control tests were performed to verify the efficacy of the TSS to effectively prevent losses. All screenings demonstrated the TSS would be well-suited for the intended field application. The spacer system was successfully deployed in Caspian Sea wells and helped meet cementing objectives where conventional treatments failed.
New Horizons of Well Bonding: Cement Expansion in Absence of Water Access
Authors: Bakhareva Elizaveta , Sukhachev Vasilii , Sozonov Alexander , Zinovyeva Anastasia , Olennikova Olesya , Akhmetzianov Ilshat
Published: October 2021

Zonal isolation for primary cementing is generally of concern when there is potential for gas migration. The challenge for the industry is to achieve a long-term annular cement seal and prevent gas migration. This paper focuses on the problem of ensuring sufficient bulk expansion of set cement without access to external water and optimizing the cement slurry formulation. The approach to solving this problem is creative and simple within the industry.

One of the reasons for wellbore gas migration and inter-connected flows can be due to cement shrinkage over time. This study focuses on laboratory testing of an expanding cement system in the absence of water and analysis of test results of novel the cement system in terms of its implementation on well with high gas migration potential. The cement system behavior will also be described in terms of rheological, filtration and mechanical properties and compared to conventional expanding cement slurries. This approach can be used to improve cement bonding with the aim of minimizing future remedial jobs.

Several approaches were implemented to achieve noticeable expansion in anhydrous media. One of the methods showed it was feasible to achieve 1.27% linear expansion in set cement without external water contact, while linear expansion in the presence of water was 0.78%. This method uses the addition of sodium chloride (NaCl) and while it has been previously described in literature, no practical design/testing directions have been given. The study identified the most effective concentration of sodium chloride required for set cement expansion without water availability. The study described how other cement system properties permitted better results in terms of placement quality of highly salt-saturated cement. Overall, complex laboratory test results provide evidence of effective linear expansion in set cement in the absence of external water. The optimization of cement slurry properties was focused on obtaining optimal thickening time, rheology and compressive strength, which was complicated by the presence of a high concentration of sodium chloride.

An expanding cement system was successfully tested in the absence of water showing positive linear expansion. A new approach for testing expanding cement systems in the absence of water was introduced how excessive linear expansion could be compromised with compressive strength development. The research results have shown that the use of NaCl additive in high concentrations in high SVF self-healing systems provided improved performance when aiming for effective linear expansion in set cement in the absence of water.
Propagation of Nano Sized CDG Deep into Porous Media
Authors: Veliyev Elchin F. , Aliyev Azizaga A.
Published: October 2021

Enhanced Oil Recovery (EOR) technologies become more critical as number of mature oilfields grows continually. Among the variety of chemical EOR methods, conventional application of the polymer-based solutions occupies the largest space. One of the most perspective technologies is application of polymeric fluids that do not contain a 3D polymer structure. Among such compositions, colloid dispersion systems are especially worth mentioning as they could be simultaneously used for water-oil mobility ratio control as well as permeability profile modification. Presented study considers the propagation of colloidal dispersed gels in porous media under different mineralization of formation water. For this purpose were conducted rheological measurements, Particle size distribution and Propagation experiments. The results show that divalent ions cause higher viscosity reduction due to the formation a more severe electrolyte and average particle size decreased with ionic strength increment. The presence of divalent ions improves the propagation probably by cause of repulsion forces increase.
Integration of Thermodynamics in Ensemble Modeling for Gas Development Project
Authors: Mollayev Rovshan , Aliyev Aghamehdi
Published: October 2021

Study was conducted to evaluate development of gas-bearing formations in the Azerbaijan sector of the Caspian Sea. Study considered subsea wellheads tied into subsea manifold, and that manifold tied to offshore facility. Flow Assurance required the calculation of subsea Flowing Wellhead Temperature (FWHT) and Pressures (FWHP). 242 subsurface scenarios were conducted with reservoir model. To accommodate all subsurface scenarios in flow assurance assessments, it was required to carry out FWHT/P calculations for all.

Reservoir model was equipped with vertical lift performance curves for pressure loss calculations in tubing and logic for pressure loss estimation in subsea system. If correctly calculated, [FWHP >= dP(subsea) + Pseparator] logic should have been satisfied. As the reservoir model was not set for FWHT calculations, an external tool was required to cope with that task. Both nodal analysis software and dynamic flow modeling were considered as appropriate tools. However, as nodal modelling allowed much more automation, it was decided to use nodal analysis over dynamic modelling.

To improve FWHP calculations:

the logic was built into the reservoir model to: ○  estimate dP(subsea) from gas rate vs pressure drop curves ○  confirm validity of [minFWHP(wells 1, 2…n) >= dP(subsea) + Pseparator] statement: step was re-iterated until the statement was satisfied

To improve FWHT calculations:

Enthalpy Balance method was tested for gas wells with 1-2% error against actual data Then, nodal analysis models with the same method were built for the project wells Code was developed to calculate FWHT as part of the ensemble model predictions in following steps: ○  Well properties of each prediction step were transferred to nodal analysis software. ○  kH was varied until nodal analysis software calculated gas rate matched to ensemble model output within 1mmscf/d error

Summary:

Described methods allowed to significantly increase accuracy in FWHT and FWHP calculations and accommodate all possible subsurface scenarios in Flow Assurance evaluation Integration of subsea and topside hydraulics in subsurface modelling is important to develop flow assured design for development Enthalpy Balance temperature prediction method provides good match to actual data Use of coding provides huge opportunities to automate data analysis

Paper will present different approach to calculation of FWHT and FWHP in subsurface modelling, integration of subsea and topside hydraulics in subsurface modelling via alternatives ways, use enthalpy balance temperature modelling, integration between nodal analysis and subsurface modelling and coding can prove analysis of large subsurface data set.
Exploration and Formation Testing of Low Permeability Clastic Reservoir in Hot Slim-Diameter Open-Hole Well
Authors: Blinov Vladislav , Koshevaya Elena , Ramatullayev Samat , Filimonov Anton , Shteynbrenner Kirill , Zhabagenov Muratbek
Published: October 2021

The objective of the logging campaign was to explore the hydrocarbon deposits in low-permeability clastic reservoirs utilizing an advanced logging suite and a high-tech wireline formation tester (WFT). The exploration well, which had a diameter of 146 mm and was drilled to a vertical depth of 4750 m, had a temperature of 147 degrees Celsius downhole.

Despite the challenging geological and downhole conditions: low permeability reservoir, high reservoir temperature, small wellbore diameter, and very high salinity drilling mud, the advanced logging suite data, which included nuclear magnetic resonance (NMR) and cross-dipole broadband acoustic logging, was successfully acquired. The WFT, which consists of a unique radial probe technology for efficient sampling of extremely low-permeability formations and a downhole fluid analyzer to determine the nature of the inflow and make rapid operational decisions in real time, was then used to perform downhole fluid analysis and sampling stations.

Oil and gas-saturated reservoir intervals were identified, their porosity, water saturation, and permeability were evaluated, and an optimal open hole WFT program was produced as a result of the extended logging suite's interpretation. Special technological operations were performed during well logging in this well, allowing for the acquisition of high-quality NMR data under extreme conditions. Rapid processing and interpretation of well logging data, performed without any a priori reservoir data, allowing for the identification of the best permeability intervals in oil and gas-saturated reservoirs and the design of an optimal WFT program in an open hole. Downhole fluid analysis and sampling stations were performed with WFT with pressure build-up to determine fluid mobility to validate the presence of productive intervals. Thus, in several downhole trips in a relatively short period of time, potential hydrocarbon layers were assessed in an open hole section, and in the presence of sufficient fluid mobility, the saturation of the interval was determined by WFT. It is important to note that downhole gas samples were acquired in intervals having fluid mobility less than 0.06 mD/cP, where the conventional well test would most probably fail to induce a flow without stimulation.

An integrated approach using modern well logging methods made it possible to solve the set geological challenges in the extreme conditions in this exploration well, where traditional methods would introduce significant uncertainties.
Expanding the Capabilities of Modern Wireline Formation Testers for Understanding the Structure of Tight and Fractured Suprasalt Carbonate Field in West Kazakhstan
Authors: Blinov Vladislav , Shutang JIN , Ramatullayev Samat , Filimonov Anton , Zhabagenov Muratbek , Shteynbrenner Kirill , Fu Gongwei
Published: October 2021

Low porosity carbonate reservoirs of the Carboniferous and Devonian periods of the Caspian Basin in Western Kazakhstan are challenging to characterize using traditional well logging methods due to the complex structure of the pore space, which necessitates lengthy and sometimes ineffective production well tests. Limitations of standard well logging methods make it impossible to reliably identify productive reservoirs, determine boundary conditions, and delineate saturation. As a result, a unique approach is required, which includes the integration of special "high-tech" logging tools and wireline formation testers (WFT). This paper effectively demonstrates the use of this approach in an appraisal exploration well.

The use of a wireline formation tester in conjunction with modern complex fluid analyzers and a radial probe allowed for testing several carbonate intervals with extremely low-permeability in one trip, which previously required stimulation to trigger fluid inflow in a cased well. This provided a new perspective on understanding the reservoir structure in the shortest amount of time possible.
Tectonic Criteria of Oil and GAS Potential at the Transitional Part of the Susha-sea Along the Western Coast of the South Caspian Depression
Authors: Aslanov Baylar , Jabizade Nurlan , Khuduzadeh Arastun , Aslanzade Fidan
Published: October 2021

The southern part of the South Caspian oil and gas Basin (SCB) is one of the main oil and gas producing regions in the central part of Eurasian continent. The large number of offshore oil and gas fields is located here, therefore the basin considered as a promising direction for the further perspective zones survey.

The basin is located between the uneven-aged mountain structures of the Lesser and Greater Caucasus in the west, the Great Balkhan and Kopet-Dag in the east, the Talish and Elbrus ridges in the south. In the north, it is limited by a sub-latitudinal regional deep fault, which fixes the northern slope of the complex Absheron-Balkhan zone of uplifts, which is part of the South Kura and Western Turkmenistan depressions. Among the structural elements of the second order, the South Absheron depression, the complex Abikh swell and the Javadkhan-Natevan zone in the west should be noted; Turkmen terrace, Ogurchinskaya step and Chikishlyar-Fersmanovskaya-Weber-Western zone in the east (Fig. 1).

The central place in the structure of the basin is occupied by the South Caspian Mega Depression (SCMD), in the most submerged part of which - the pre Elbrus Basin - the basement lies at a depth of about 25 km, and the sedimentary stratum, including Mesozoic, Cenozoic and Quaternary formations, is largely represented by the Pliocene - post-Pliocene sediments, reaching a total thickness of 8–10 km and more in the troughs (Fig. 2, 3).
Organic Geochemical Characteristics of Core Samples from Central Primorsk-Emba Province, Precaspian Basin, Kazakhstan
Authors: Jarassova Tolganay , Altunsoy Mehmet
Published: October 2021

The Primorsk-Emba province is one of the main oil and gas region of the Precaspian basin. The resources of the Primorsk-Emba oil and gas region range from 5 to 12 billion tons of oil and from 2 to 6 trillion m³ of natural gas. This study primarily concentrates on investigating the organic geochemistry and petroleum geology characteristics of sedimentary units that generated oil in the central Primorsk-Emba province. 20 core samples taken from the Jurassic units in the western part of the study area are characterized by organic matter amount, hydrocarbon production potential, type of organic matter, maturity of organic matter. According to the Rock-Eval results Jurassic aged rocks generally have a petroleum potential ranging from weak to excellent, the organic matter is between Type II (oil prone), Type II-III (gas-oil prone) and Type III (gas prone), and the degree of maturation is immature-mature stage. Oil extracts were characterized by geochemical methods including Gas Chromatography (GC) and Gas Chromatography–Mass Spectrometry (GC–MS). n-alkanes and isoprenoids were evaluated by High-Resolution Gas Chromatography (GC-HR), aromatic hydrocarbons were evaluated by Low Thermal Mass Gas Chromatography (GC-LTM), terpanes (hopanes), steranes / diasteranes and aromatic hydrocarbons were evaluated by Gas Chromatography-Mass Spectrometry (GC-MS). The GC and GC-MS data obtained, it has been determined whether the paleoenvironment characteristics of the study area, hydrocarbon potential, type of kerogen, maturity level of organic matter and whether it is affected by biodegradation. Distribution of n-alkanes in the GC showed that no biodegradation was observed in analyzed samples, source rock deposited in a marine environment under reducing conditions and an organic matter that occurred were generated by marine carbonates. Based on maturity parameters, studied oils are mature and located on the oil generation window. According to biomarker age parameters C28 / C29 and norcholestane (NCR)/nordiacholestane (NDR) samples are generally Mesozoic (Triassic-Jurassic- Cretaceous) origin, nevertheless there are also levels corresponding to the Paleozoic (Permian) late stages.
Influence of Secondary Alterations on the Structure of the Pore Space of the Upper Permian Carbonate Deposits of the Northern Side Zone of the Caspian Basin
Authors: Ayupov Amir Rustamovich , Khafizov Sergey Faizovich , Iskaziev Kurmangazy Orinbgazievich
Published: October 2021

The analysis of the facies distribution of reservoirs within the Moscow-Artinskian sedimentation rim within the Northern part of the Pre-Caspian Basin was carried out.

The Teplovsko-Tokarevskaya group of deposits is a chain of carbonate structures stretched in the sub-latitudinal direction. They are consist mainly of bioherm structures, which include tubifytes, foraminifera, crinoidea, ostracods, ostracods, etc.

From the lithological point of view, the reservoir rocks are represented by dolomite-limestone differences-from organic limestones to secondary chemogenic dolomites. The influence of facies distribution and secondary dolomitization on the structure of the pore space remains controversial and requires detailed study.

The concepts of secondary dolomitization were analyzed and one of the concepts of the formation of secondary dolomites and anhydrites was used to justify the facies distribution: Zones of secondary transformation (dolomitization) form a sweet spots zone in the Artinskian carbonate horizon when high-salinity (Mg2+) waters from the Filippovsky horizon carbonates are infiltrates to Artinskian carbonate. As a result of the discharge of elision waters during digenetic dehydration of gypsum. After the anhydride overlaying of the Artinskian carbonate structure, several regressive-transgressive cycles occurred, which formed a sequence of consistent dolomite-limestone and gypsum layers in the Filippovskian time. During the diagenesis water contained in the gypsum was dehydrated into the permeable zones in carbonates of the Filippovsky horizon, followed by unloading in the region of the Artinskian horizon.

Evaporite sedimentation of chemogenic carbonates and gypsum created a condition for the subsequent infiltration of sulphate and magnesium waters in the direction dip formation angle. The source of magnesium is the water remaining after the precipitation of gypsum and carbonates in the Filippovskian time.
Changing Patterns of Learning in Oil and Gas Industry
Authors: Hajiaghabayli Ferid , Babayeva Elnara , Haydarov Mehman
Published: October 2021

Covid-19 pandemics have made innovations even more crucial and used them to take market power over competitors considering challenges that the world and global economy face. To achieve this goal, organizations need competent and high-expertise human capital as a workforce. That is one of the key reasons organizations increase their investment in developing, re-skilling and up-skilling their workforce via various learning and development programs and solutions compared to previous years.

Given the direct impact of this process on the company's revenues, the following graph demonstrates the value flow generated (Figure 1):

Organizations aim to ensure minimum time and efficient expenditure structures to achieve and build a learning system that delivers sustainable developmental solutions and interventions. Knowledge sustainability is a purpose, which focuses on various learning methods and solutions to make knowledge last and kept longer.

A learning management system (shortly, LMS) is a platform that gathers all the learning solutions in one place and automates the process of learning to present development opportunities to end-users - learners/employees. Digital learning enables users/employees to develop their competencies quickly, no matter the place and time and makes knowledge and information accessible for all, and gives an unlimited option to relearn, repeat and refresh anything already completed unlimitedly.
The UNFC Concept and the Possibility of its Application in Azerbaijan
Authors: Garayeva Narmina , Zeynalov Gasham , Ahmadov Elkhan , Hajiyev Agarza , Rahimov Farid , Aslanova Aida
Published: October 2021

Moving towards sustainable development, Azerbaijan joining SDG Agenda 2030 adheres to the policy of developing both hydrocarbon and non-hydrocarbon resources for economic diversification. At the same time, efficient resource management becomes a vital process at the governmental and transnational companies’ levels. Therefore, a competent classification and structuring of all reserves and resources will be inevitable soon to improve their accurate estimates and effective management in various aspects, including resource availability, technical feasibility, and environmental-socio-economic viability. The importance of the latter is indisputable since social and environmental stability is an essential component of the country's sustainable economic development policy.

From this perspective, the United Nations Framework Classification for Resources (UNFC) is seen as a tool to help accomplish these tasks and provide simple screening and verification procedures for evaluating future investment projects.

Given that hydrocarbon reserves make a significant contribution to the economy, a study on the application and adaptation of UNFC to local petroleum resource management has been granted as a pilot project to assess the feasibility of its further implementation for other energy and mineral reserves and resources of the country. The UNFC current state analysis as a global standard for classifying energy and mineral resources and their applications is carried out to launch the project. The review covers various case studies, including the classification of hydrocarbon reserves and resources (HCRR) using UNFC (Mexico project, transition projects to the classification of the Russian Federation, etc.), as well as mineral resources in different countries.

The research primary goal is to screen different approaches and techniques to assess the practicality of their application to petroleum reserves and resources of Azerbaijan in transferring currently used old Former Soviet Union HCRR classification to UNFC, possibly via PRMS. In addition, a Case Study Research based on the Field A data in Azerbaijan is conducted.
Designing the Thermal Enhanced Oil Recovery as a Key Technology of High Viscosity Oil Production
Authors: Shaken Mukhtar Shakenuly , Zhiyengaliyev Baurzhan Yerikovich , Mardanov Altynbek Suleymenuly , Dauletov Adil Sultangaliyevich
Published: October 2021

Due to the decrease in "easy" oil reserves, oil companies are focusing on "hard-to-recover" reserves, in particular, high-viscosity oil reservoirs. Shallow oil reservoirs are mainly concentrated in the Cretaceous horizons, in the western region of the country, along the Caspian coast. One of them is a high-viscosity oil reservoir, consisting of three Cretaceous horizons. The average viscosity of oil in reservoir conditions is around 746.7 cP. The current achieved oil production is only 5% of the initial recoverable reserves, and designed oil recovery factor is 38% and implies the full-scale application of thermal methods of EOR.

The objective of this work was to choose the most suitable thermal method of EOR and to assess the prospects of applicability with the calculation of economic feasibility. Considering the geological features of the reservoir, the cyclic steam stimulation was chosen as the optimal method to increase oil recovery. In order to assess the expediency of this technology, was initiated project on thermal modeling the technology based on the current geological and hydrodynamic model of the field, using the results of laboratory studies, calculations were performed on imagined horizontal wells, and carried out the analysis of technical and economic efficiency.

According to the results of calculations on the hydrodynamic model, the production rates using the technology of cyclic steam stimulation in horizontal wells are 30% higher than the production rates of "cold production", and the difference in accumulated oil production over 5 years will be 20–30%.
Application of Hybrid Biosystems for Stimulation of Oil Production
Authors: Suleimanov Baghir Alakbar , Rzayeva Sabina Jahangir , Akhmedova Ulviyya Tahir
Published: October 2021

Microbial enhanced oil recovery is considered to be one of the most promising methods of stimulating formation, contributing to a higher level of oil production from long-term fields. The injection of bioreagents into a reservoir results in the creation of oil-dicing agents along with significant amount of gases, mainly carbon dioxide. In early, the authors failed to study the preparation of self-gasified biosystems and the implementation of the subcritical region (SR) under reservoir conditions.

Gasified systems in the subcritical phase have better oil-displacing properties than non-gasified systems. The slippage effect determines the behavior of gas–liquid systems in the SR under reservoir conditions. Slippage occurs more easily when the pore channel has a smaller average radius. Therefore, in a heterogeneous porous medium, the filtration profile of gasified liquids in the SR should be more uniform than for a degassed liquid.

The theoretical and practical foundations for the preparation of single-phase self-gasified biosystems and the implementation of the SR under reservoir conditions have been developedSR under reservoir conditions. Based on experimental studies, the superior efficiency of oil displacement by gasified biosystems compared with degassed ones has been demonstrated. The possibility of efficient use of gasified hybrid biopolymer systems has been shown.
Concentric Coiled Tubing, Proven Sand Cleanout Technology for Sub-Hydrostatic Wells in Caspian Sea
Authors: Hasanov Emil , Mammadov Hajagha , Correa Pedro
Published: October 2021

Influx of sand production is one of the major issues faced in oil and gas wells on the Caspian region. Although there are multiple technologies to address this issue, the application of these technologies require the well to be cleaned before proceeding with any kind of remedial application. Concentric Coiled Tubing (CCT) sand vacuuming technology has brought a massive advantage for efficiently cleaning the wellbore of sub-hydrostatic wells in Caspian Sea.

CCT system is the Coiled tubing string inside of Coiled tubing string which essentially provides a smaller second annular return route for the wellbore solids while simultaneously boosting the return pressure and allowing to clean the sand where the bottomhole pressure (BHP) is low and not enough to support the circulation of fluids used for the cleanout. Cleanout fluid is pumped through the inner string to power the downhole jet pump comprised in CCT bottomhole assembly (BHA) which creates a drawdown that vacuums the solids and circulates the solids back to surface via the CCT annulus.

The solid performance of the CCT system has an established track record worldwide and application of this sand cleanout technology brought a solution for recovering many wells with low BHP and has been successfully implemented since 2013, providing a method for cleaning out tons of accumulated sand particles from challenging wells in Caspian Region. With the complex system being used for cleaning out sand and also surface handling of the solids in the return flow from the wellbore, CCT sand vacuuming technology has proven to be effectively functioning in all cases that it was selected for so far.

This Paper reviews the design and mechanism of the CCT sand/well vacuuming system as well as the results of several well intervention cases with its successful execution and lessons learned in Caspian region.
Field-Proven Well Surveillance Techniques Designed for an Early Well Scaling Diagnosis and Timely Well Performance Reinstatement: Case Study from the Kashagan Field
Authors: Kauzhanova Aktoty , Te Lyudmila , Reedy John , Ehighebolo Thaddeus Ivbade , Heinerth Mirko Bastiaan , Khaidarov Yerbol
Published: October 2021

Some wells in the Kashagan field did not perform as well as expected. Despite producing virtually no water, calcite deposition was found to be the root cause of the problem. A comprehensive well surveillance program, which was proven to be very efficient for an early scaling diagnosis, was developed by the operator, North Caspian Operating Company (hereafter NCOC). As a result, well scaling is currently well managed and prevented from reoccurring. The objective of this paper is to share an early experience with well scaling in the Kashagan field, as well as to describe the developed set of well surveillance techniques.

The aim of the various well surveillance techniques discussed in this paper is to improve an Operator's ability to identify the very first signs of scale accumulation. This, in its turn, enables to introduce timely adjustments to the well operating envelope and to schedule a scale remediation / inhibition treatment with the intention to prevent any potential scaling initiation from further development. The approach is quite extensive and incorporates continuous BHP/BHT monitoring, routine well testing, PTA analysis, and fluid/water sampling.

Developed approach experienced multiple revisions and modifications. Further optimization continues, however, the described well surveillance techniques represent the latest Operator's vision on the most efficient way for well scaling monitoring and identification. In the Kashagan field, BHP/BHT readings have proved to be the most direct and instantaneous indication of any early signs of potential deterioration in well performance (qualitative analysis) while well testing and PTAs are considered as the most essential techniques in confirming and quantifying scaling severity (quantitative analysis). It is important to mention that BHT increase is explained by Joule-Thomson heating effect being specific for the Kashagan fluid (happening during increased pressure drawdown). This, in turns, enables to predict future well performance, design well operating envelop accordingly and, most importantly, develop a yearly schedule for proactive well treatments with SI.

In conclusion, it shall be highlighted that discussed complex of well surveillance techniques has been concluded to be very efficient and reliable tool in identifying any scaling tendencies at its initial stage. Due to successful implementation of this approach in the Kashagan field, scale development is now well-managed and kept under control. To mention, that utilization of well surveillance techniques and methods outlined in this paper may reduce the time required to identify and ultimately mitigate well scale accumulation in any active assets with similar operating environments.