bluuebunny/crossref_metadata_2025_split huggingface dataset:
Well Control and Management: Killing Fluids for Oil Fields of JSOC Bashneft
Authors: Karpov Al. A. , Vakhrushev S. A. , Sitdikov M. R. , Zdolnik S. E. , Kuzmin A. M. 
Published: September 2014

Abstract
Today well killing operations form an integral part of routine well control and management. Therefore the essential task is to select an optimum killing fluid for the given conditions which would secure safety of well operations by preventing any entry of formation fluid into the wellbore with no risks of formation damage in the near wellbore zone. At the same time killing fluids should be available on the market, easy to use and readily producible at a wellsite.
The use of water-based killing fluids may result in a very long well stabilization time after the operation and reduced well productivity. The most important factors which affect an oil reservoir are the invasion volumes of a killing fluid, its compatibility with formation waters and hydrophilic minerals in the formation rock.
Most fields operated by JSOC Bashneft are characterized by the presence of highly mineralized water bearing beds in the section with density up to 1.18 g/cc. This water is used as a killing fluid and if necessary can be mixed with fresh water to get a mixture of a certain density for the required back pressure on the formation.
The paper discusses risks of scaling when a killing fluid is prepared and mixed with formation waters from various horizons. Within the scope of this study laboratory tests were performed on core to assess the risks of formation damage and reduced permeability in the result of killing fluid invasion into a reservoir.
Given such geological and engineering conditions the design of killing operations should integrate optimization of killing fluid properties with the use of various chemical agents which would prevent any formation damage and protect well equipment.
Problems of Oil and Gas Production Associated With Gypsum Depositing in the Verkhnechonskoye Oil and Gas Condensate Field
Authors: Chertovskikh E. O. , Alekseev S. V. 
Published: September 2014

Abstract
The article is devoted to the problem of scaling in the Verkhnechonskoye oil and gas condensate field. The history of gypsum scaling in VC Field is briefly reviewed. Presented are results of studies conducted in the oil field conditions to select and justify an appropriate technological solution for removal of the gypsum scale. The gypsum removal technology envisages well treatment with a fluid containing caustic soda. Potential causes of gypsum scaling in VC Field are revealed with reference to results of analyses of the consolidated field database. A theoretical justification of geochemical conditions of gypsum scaling in VC Field is proposed. Wells located in gypsum-scaling risk zones in VC Field are identified. The authors give recommendations concerning development of the gypsum removal technology for VC Field.
How IT Technology is Changing the Established Approach to Safety and Reducing Operational Risks
Authors: Rykov Kirill 
Published: September 2014

Abstract
According to best practices, reducing the occurrence of an undesirable event is possible by organizational and technical changes. Organizational changes are mainly related to the implementation of enterprise policies to reduce operational risks and improve operational safety based on standards BS 8800, OHSAS 18x series, ISO 14x series. Technical changes are mainly associated with modification of old equipment to modern, reliable equipment, and with integration of information systems in everyday business activities. These systems support daily activities through creating an information platform for: communication, violations data collection, dangerous situations, emissions, discharges, etc. Accumulated data is in turn used both for analyzing the current situation and predicting possible progression of events, relying on short-term data passed to the system in real-time mode, historical data on the already occurred accidents, incidents, and the prediction logic.
This review article is dedicated to the changes that IT technologies introduce into the environmental and operational safety. It is explained how to use mobile technologies, 3D visualization and operational work with a significant amount of structured and unstructured data for proper understanding and even predicting events.
As a result, the reader will gain an insight into state-of-the-art capabilities of IT technologies in the field of environmental and operational safety, possible difficulties while integrating them into the business environment, the benefits obtained and the business prospects.
Russian Offshore: Gained Experience and Development Perspectives of the Northern Block of the Caspian Sea
Authors: Svarovskaya M. , Senkov A. , Zolotukhin A. 
Published: September 2014

Abstract
Russia being one of the main feedstock suppliers for the world's power generation has, however, a relatively small experience in modern development technologies for offshore fields. In terms of this fact one of the key projects recently put into a full-scale development phase (2010) is Yuri Korchagin field in the northern part of the Caspian Sea. This area includes several oil, gas and gas condensate fields that are now at various stages of their preparedness for startup. Yuri Korchagin oil and gas condensate field features the whole sequience of modern solutions for exploration, development and production of hydrocarbons and performance of R&D activities.
This article describes main results of implementing the design solutions developed for Yuri Korchagin - the first industrially operated field in the North Caspian. The article studies the effectiveness of the selected development scheme for the oil and gas condensate deposit and summarizes the experience in risks management both for technological (drilling, completion and production) and geological (reservoir data and modeling) issues. The article also describes the challenges of expanding the resource base in the area operated by OOO "LUKOIL-Nizhnevolzhskneft". This information can be useful for updating the status of current offshore development projects. Furthermore, this experience could be very useful in developing fields containing an oil rim.
Development of Carbonate Reservoirs with Complex Trajectory Wells in Republic of Tatarstan
Authors: Akhmetgareev Vadim , Idiyatullina Zarina 
Published: September 2014

Abstract
Research and development in the area of complex trajectory well drilling technologies, including combined with hydraulic fracturing treatment, is one of the first priorities for national and international oil producers, OAO TATNEFT is no exception.
As of 1 January, 2014, in TATNEFT oil fields, 587 horizontal wells and 104 multilateral wells have been drilled, including 421 horizontal wells and 83 multilateral wells drilled in carbonate reservoirs. On the average, initial oil production rates of horizontal and multilateral wells are higher vs. vertical wells, 1.8 times and 2.4 times, respectively. The worst production parameters are characteristic of horizontal and multilateral wells, 77 and 32 wells, respectively, draining the Bashkirian-Serpukhovian formations, which testifies to poor efficiency of horizontal technologies in this type of reservoirs. Of the total number of wells targeting carbonate formations, 11 multilateral and 15 horizontal completions showed good well performance.
The paper presents a number of technologies aimed at improved carbonate reservoir performance through complex trajectory wells. Optimization of development of the carbonate reservoirs in the Pionerskoye, Novo-Elkhovskoye, and Shegurchinskoye fields will allow reducing vertical drilling metreage, thus, saving on well construction and infrastructure cost. It will also result in improved reservoir flow behavior, connectivity, and enhanced oil production. It is deemed that oil production of complex trajectory wells will increase 1.5-fold vs. vertical wells. The offered horizontal technologies will help to achieve uniform oil drainage of heterogeneous formations with different reservoir properties and, increase water-free production of wells through use of expandable well completion systems involving packers and ICVs or water-swellable packers. Calculation made in reservoir models show ultimate oil recovery increase by 8-15%. The Company is planning to commercialize the technologies in the nearest future.
Application of Data Mining Tools for Analysis and Prediction of Hydraulic Fracturing Efficiency for the BV8 Reservoir of the Povkh Oil Field
Authors: Alimkhanov Rustam , Samoylova Irina 
Published: September 2014

Abstract
The technique for selecting candidate wells for hydraulic fracturing and prediction of post-frac well performance using Data Mining tools (neural networks, decision tree algorithm, etc.) is presented. The technique was applied to the BV8 reservoir in the Povkh Oil Field. The reservoir is characterized by the complex clinoform structure.
The objective of the paper is to determine basic criteria for candidate selection and evaluate the effect of different geological and field conditions on the efficiency of hydraulic treatments. To achieve the objective two problems have been solved: Development of classification models (efficient/inefficient hydraulic fracturing treatment);Development of regression models (post-frac fluid rate, water cut, oil rate).
Machine learning algorithms were used in petroleum industry in the past, but neural networks is the most common technique. Eleven models have been built based on six algorithms. A comparison has been made between the models. A good consistency between predicted values of post-frac fluid rate and water cut and actual results has been revealed.
Major geological and field criteria for the efficiency of hydraulic fracturing operations have been identified. The models built can be applied to predict the post-frac performance of a single well as well as to do a quick estimation of the whole well stock. The results presented show significant predictive power of the Data Mining tools for geologically-complex reservoirs. It should be assumed that the usage of the technique for less complex reservoirs will allow us to significantly improve prediction of well performance.
Successful Placement of Cement Plugs in HP/HT Wells Using an Innovative Computer-Aided Simulator
Authors: Guo Y. , Zhang X. , Taoutaou S. , Li T. , Li Y. , Lian Y. , Huang S. , Peng Y. 
Published: September 2014

Abstract
Placing cement plugs in high-pressure/high-temperature (HP/HT) wells represents a big challenge, from the standpoint of both the chemistry and the placement techniques. Any failure to properly place a cement plug will lead to costly nonproductive time and will require repeating the job, which represents even more technical and operational challenges because of the downhole uncertainties.
West China's Tarim basin experienced these challenges for HP/HT sidetrack, plugback, loss circulation, and abandonment cement plugs, with wellbore depth over 6500 m and bottomhole temperature over 160 °C. To improve the success rate of placing cement plugs, thorough analysis of well information was done, and novel placement software was implemented to help ensure a successful placement.
The new computer-aided model is a risk-based model that takes into account the downhole well conditions to analyze and display the fluid interfaces of mixing, both while traveling inside the pipe and in the annulus. The result is the assessment of the possible contamination of the cement slurry after pulling the pipe out of the hole and a recommendation for the best fit to execute a successful cement plug. The results obtained with the new engineering tool and precise operational field executions allowed the operator to execute more than 80 cement plugs successfully from 2010 to 2013.
The Twilight of Energy Abundance
Authors: Archibald David 
Published: September 2014

Abstract
The discovery of the giant East Texas Field in 1930 started a period of inherent oversupply of oil that ended in 2004. The oil price has tripled since 2004 while conventional oil production has remained static. Production has not been able to respond to the price signal provided because it is constrained by geological factors. Logistic decline plot analysis indicates that the world consumed half its conventional oil endowment by 2005. Ten years later, production is on the cusp of a long decline at a rate of 1.5 million barrels/day/annum. OPEC production will start declining later than non-OPEC production with both at 27 million barrels per day in 2030, 27% lower than the current plateau level. Tight oil production in the US is expected to peak at about 4 million barrels per day in 2018. A contribution to supply from tight oil production elsewhere in the world will be delayed due to geological, cost and regulatory factors. The price response to the contracting supply of conventional oil will lead to price-driven substitution of liquid fossil fuels by natural gas and synthetic fuels from coal, in turn enhancing the economics of nuclear energy in the electric power market. World coal production will peak in 2021 due to the peak in Chinese production that year. Ultimately the level of civilisation humanity will enjoy will be dependent upon the cost of nuclear power and the production of synthetic liquid fuels using hydrogen electrolysed from water and carbon from farmed sources.
A Cross-Link Polymer Sealant for Curing Severe Lost Circulation Events in Fractured Limestone Formations
Authors: Al-Azmi Bader , Al-Mayyan Haitham , Al-Saleh Fawaz , Godara Vijay , Panchal Rakesh , Kosandar Balraj , Tobeh Samir , Jadhav Prakash , Yadav Prahlad , Samir Ahmed 
Published: September 2014

Abstract
Preventing and curing fluid losses in limestone formations is one of the most challenging loss situations to prevent and control. Loss zones are unpredictable, due to large vugular zones and extended and connected fracture structures. Often these limestone intervals are depleted reservoirs. Typically, calcium carbonate pills containing various size distributions are part of the lost circulation armory in reservoir sections. However, results are highly variable and not suitable for large-scale losses. This is distinguished for those situations with the most-severe lost circulation, where chemical sealants may be more applicable than treatments by plugging particles.
The paper discusses about use of a cross-linking polymer fluid treatment that enables operators to cure lost circulation zones in many different applications, providing distinct operational and economic advantages over conventional reactive and temperature activated methods.
The paper discusses the customization of the polymer fluid to have specific thickening or setting time so this loss circulation fluid can be pumped through the existing bottomhole assembly (bit nozzle size greater than 14/32nd) without losing rig time associated with tripping and mixing conventional loss circulation material treatments (LCM). The paper discusses the execution procedures and cautions to be followed to improve cross-link LCM plug placement as well as chances to arrest losses.
Due to biodegradable nature of organic cross-linking polymer plugs, it was used in sensitive reservoirs with minimal effect on the formation. The cross-linked plug or pill, with time and temperature, will break back to a fluid state and may be produced back and circulated from the wellbore.
The discussions in this paper will further reveal the workings and applicability of cross-link polymer fluid to lower costs for drilling fluids, cementing and casing design.
Reinforced Composite Mat, a Proven Solution for Lost Circulation Control in Sumatra Field
Authors: Pasteris Mathieu , Taoutaou Salim , Simanjuntak Andre , Kusumawatie Reny 
Published: September 2014

Abstract

DESCRIPTION
One of Indonesia historic oil producing field in the Sumatera Island is constantly developed in order to maintain production at a sustainable level. The number of wells drilled is between 250 and 400 per year due to the highly depleted nature of the field. One of the main issues that jeopardize the drilling efficiency in this field is the challenge of drilling and cementing under losses; this can result in a poor cement job quality and/or not being able to bring cement up to surface. A bad zonal isolation can cause loss of steam efficientcy, excessive water production and loss of well integrity requiring costly remedial jobs yielding delayed production since the heavy oil reservoir in this area is produced using the enhanced production technique of steam flooding

APPLICATION
A solution implemented to cure the losses during the drilling and cementing consists of a newly developed reinforced composite mat fiber and granule based loss circulation solution coupled with a diagnostic computer aided software. The Software validates the efficiency of the pill design in curing the losses while drilling and/or cementing. A total of 50 wells were treated, this technology was used in 48 wells while cementing and 2 wells while drilling with a high success rate.

RESULTS OBSERVATIONS AND CONCLUSIONS
This paper will first detail the standard techniques that were used historically in order to combat losses while drilling, then will describe the new approach using the reinforced composite mat technology, and shows quantitative results achieved mitigating lost circulation challenges and ensuring competent zonal isolation which led to eliminating remedial work in more than 60% of the wells.

SIGNIFICANCE OF SUBJECT MATTER
This innovative approach has increased success rate in bringging cement back to surface during well construction on the first attempt from 2% with conventional techniques to more than 60% using Composite Mat Fiber Technology.
Geomechanical and Reservoir Integrated Hydraulic Fracturing Optimisation for a Tight Oil Reservoir: A Case Study from Offshore Vietnam
Authors: Rahman Khalil , Gui Feng , He Wei 
Published: September 2014

Abstract
Producing tight oil reservoirs by hydraulic fracturing is especially challenging due to relatively low oil mobility. At the planning stage, an integrated approach is essential to optimise fracture parameters using a reliable geomechanical model and reliable reservoir simulations to predict the post-fracture productivity and the net present value (NPV). This paper presents such an integrated case study. The reservoir contained relatively clean sandstones interlaying only a few thin shale layers. A relatively low recovery was expected to yield a good positive NPV because production was planned using a nearby existing production facility.
A geomechanical model was built using core, well log and drilling data characterizing the in situ stress, pore pressure and rock mechanical properties in the field. The reservoir properties were characterized from core-log calibration and PVT data from analogue reservoirs. The initial reservoir pressure was very close to the bubble point pressure. Thus, multiphase reservoir simulations were essential to predicting post-fracture production profiles.
The study integrated geomechanical modeling, hydraulic fracturing design, reservoir simulations and economic assessments to investigate various well completion scenarios. Various scenarios included a single vertical fracture in a deviated well, an un-fractured 1,000 m horizontal openhole well and a 1,000 m horizontal well with multiple transverse fractures. The un-fractured horizontal openhole scenario required a life cycle wellbore stability assessment. The fractured horizontal well scenario required the optimisation of transverse fractures and their spacing. The production constraints included a 600 psi tubing head pressure, a maximum oil flow rate of 5,000 bbl/d and a maximum 5-year production period with preference for more accelerated recovery.
The results from this integrated scheme enabled understanding of the impact of various well completion scenarios on decision-making based on technical and economic issues. The lessons learned in the study can be a guide for optimal development of the target field and other similar fields.
A Novel Workflow of Density Log Normalization for Coalbed Methane Wells: A Example from the Surat Basin in Australia
Authors: Ren Bin , Zhang Ming , Cui Zehong , Li Chunlei , Xia Zhaohui , Gan Thomas , Lau Hon Chung 
Published: September 2014

Abstract
In coalbed methane (CBM) projects, conventional log such density has been used heavily for coal identification, coal property derivation and also potentially for coal ranking. This paper presents a novel workflow of density log normalization for CBM wells. It addresses two major challenges to current normalization methods, namely, absence of a pervasive reference layer, and removal of geological effects after normalization.
To overcome these disadvantages, the proposed workflow undertakes six steps, which are data quality control, geological area segmentation, sub-area type well selection, density control points, variable linear transformation and quality control of log normalization results using box plots, matrix crossplots and histograms. This workflow removes the systematic errors caused by acquiring logs at different times with different logging instrument from different vendors. Furthermore, it possesses the advantages of automated quality control, Type Well Method and Reference Layer Method without incurring their respective disadvantages. It has been applied successfully to about 600 wells in the Surat Basin of Australia.
Proper log normalization will reduce the uncertainties involved in geological modeling and increase the accuracy of reservoir evaluation. This paper should therefore be of interest to petrophysicists and geologists involved in CBM field characterization.
Integrated Analysis of Shale Gas Well Production Data
Authors: Stewart George 
Published: September 2014

Abstract
In this paper the analysis of production data from shale gas wells will be considered and a workflow for the treatment of such data will be described. The methodology is based on a mechanistic model of a horizontal well with multiple hydraulic fractures and the data is analysed in terms of an average fracture half length, xf, an enhanced reservoir permeability, k, and the generated stimulated reservoir volume (SRV). Once the analytical model has been fitted to the measured pressure-rate data an advanced forecast, based on specified scenarios for the flowing bottom-hole pressure (or the wellhead pressure), is made which can be used to compute the expected ultimate recovery (EUR) over a given time frame. The integration with other sources of information commences with a review of the fracture design which will have been carried out on specialist software using rock mechanics data from acoustic logs and minifracs. The comparison of the measured transient productivity index for linear flow with that based on the fracture design parameters allows a rigorous assessment of the efficiency of the stimulation treatment. The effect of stress on formation permeability can be an important issue in the understanding of shale gas wells and an optimised choke setting strategy will be required if the effect is significant. It is shown how repeated well shut-ins (termed investigative build-ups) can be used to identify the stress effect and calibrate an appropriate geomechanics model such as the one proposed by Palmer and Mansoori. The mechanistic software can then predict future production including the observed stress effect. A new concept of pressure dependent skin is also introduced to model the deterioration of the conductivity of the major hydraulic fractures.