bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverting Injection-Induced Microseismic Monitoring Data with Coupled Flow and Geomechanical Models: Application to CO2 Injection
Authors: Hakim-Elahi S. , Jafarpour B.
Published: April 2018

High pressure fluid injection into geologic formations can trigger rock deformation and failure and lead to microseismic events. Injection induced seismicity has been proposed as a monitoring technique that can be used to constrain the description of rock flow and mechanical properties. In this paper, we present a stochastic geomechanics-based approach to establish physical correlation between rock flow and mechanical properties and microseismic monitoring data during CO2 injection. The resulting correlations are then used to estimate rock properties from observed microseismic clouds. To establish the correlations between rock properties and microseismic clouds, the developed framework combines coupled flow and geomechanics simulation outputs with Mohr-Coulomb's failure criterion to describe the spatiotemporal distribution of seismicity potential in the formation (i.e., a map that quantifies the probability of geomechanically-induced seismic events at different times and locations in the formation). The resulting seismicity potential map depends on the stress conditions and mechanical strength of the formation rock and establishes a relationship between predicted microseismic clouds and rock property distributions. This model is then used with an ensemble-based data assimilation (i.e., ensemble smoother with multiple data assimilation, ES-MDA) to estimate rock properties form observed microseismic data. Since the ensemble smoother is designed for assimilation of continuous data, kernel density estimation (KDE) is applied to convert discrete microseismic events to a continuous map of seismicity density. Furthermore, for estimation of discrete geologic facies, prior to data assimilation, a distance transformation is used to convert facies descriptions to constinuous parameters. We present the developed formulation and discuss its application to inversion of microseismic data for characterization of reservoir flow and mechanical properties. Several examples are presented to evaluate the performance of the method for estimation of rock properties from microseismic data. Our preliminary results, based on synthetic experiments, suggest that the developed method can combine coupled physics models with microseismic monitoring data to constrain the description of rock flow and mechanical properties.
Validation and Improvement of the Horizontal Pipe Separator Model
Authors: Othman H. A. , Dabirian R. , Gavrielatos I. , Mohan R. , Shoham O.
Published: April 2018

Horizontal Pipe Separators (HPS©) are used for separation of oil from oil-water mixture. It can be an attractive alternative to the vessel type separator owing to its simplicity, ease of construction, installation and operation and its lower price. An experimental and theoretical investigation on the (HPS©) were conducted. New experimental data and mechanistic modeling are presented to show the effect of different variables such as mixture velocity and water cut on the performance of the separator.

A HPS facility, consisting of a 0.0762 m ID 10.3 m long horizontal pipe has been designed and constructed. Five observation boxes are installed along the horizontal pipe to observe the development of the oil/dispersion and water/dispersion interfaces throughout the pipe. A wide range of experimental data was acquired for oil-water mixture flow behavior, and length of entry region for the oil and water separation in the Horizontal Pipe Separator was also investigated. A total of 34 runs were conducted for mixture velocities of 0.08, 0.13, 0.20 and 0.30 m/s with water cuts between 10 to 90%.

The experimental data confirm that the higher the mixture velocity, the longer is the entry region required for separation. On the other hand, when increasing the water cut, the water separation is more efficient. Similarly, decreasing the watercut results in an easier separation of the oil phase. For low water cuts (10 to 30%) and higher mixture velocities (>0.3 m/s), no separation between the phases was observed. The Gassies (2008) model has been validated and improved for water continuous flow by developing correlations for two of the Gassies model's input variables, namely, the turbulent decay time and the oil volume fraction in the dense packed zone. For water continuous phase, the comparison between the improved model prediction and the experimental data shows very good agreement for the water/dispersion interface and also for the oil/dispersion interface at low mixture velocities.
Lightweight and Ultra-Lightweight Cements for Well Cementing - A Review
Authors: Anya A.
Published: April 2018

Lost circulation is a very common and expensive problem during drilling and cementing operations in the oil and gas industry. The lost circulation problems encountered during drilling or cementing are a result of one of two factors. These factors are the presence of zones of weak fracture gradients and the presence of high permeability or thief zones downhole. Light weight cements are an effective solution for curbing lost circulation caused by the breakdown of weak zones by conventional cement slurries. This paper presents a discussion of the different methods, additives and technologies that have been and are currently employed in the formulation of lightweight and ultra-lightweight cement slurries for cementing oil wells as well as recent developments based on an extensive literature review. This paper also discusses the mechanical performance, cost effectiveness and field logistical considerations of lightweight slurries formulated using different methods as these are important factors that impact decision making on what slurry extension method to choose for any given scenario.

The information presented in this paper is derived from an extensive review of information contained in papers, journals and books spanning the last 50 years of well cementing and is summarized in such a way that the paper serves as a quick guide to cement slurry extension technology and techniques.

An extensive review of the literature regarding lightweight cements showed that there are three general methods of obtaining lightweight cement slurries. These methods include increasing cement slurry water content (water extension) with the aid of viscocifying agents such as bentonite and sodium metasilicate, adding lightweight materials like glass microspheres and incorporating foam into slurries. Reported test data shows that apart from cement slurries containing glass microspheres and foamed cements, lightweight slurries exhibit lower compressive strength and slower compressive strength development than heavy slurries. Foamed cements pose the greatest design and field logistics challenge while cement slurries with glass microspheres have gained more popularity due to the excellent compressive strength values achievable at ultra-low densities despite their higher cost compared to water-extended slurries and lightweight slurries containing other lightweight additives like fly ash.

The literature review presented also indicates a need for more research into improving lab mixing and testing methods that replicate field applications of foam cement. There is also a need for research into more cost-effective slurry extension additives and technology that exhibit acceptable mechanical performance for well integrity assurance and rheological properties favorable to proper cement placement in the annulus.
Infill Well Location Selection Procedures in Lost Hills Using Machine Learning
Authors: Kim T. H. , Crane D. J. , Grijalva E. F.
Published: April 2018

The diatomite reservoirs in Lost Hills field provide an interesting reservoir management challenge due to its unique natures such as low permeability (~ 1 md) but high porosity (~ 50%), weak rock strength, and strong imbibition. In most conventional reservoirs, numerical simulation has been successful technology in forecasting, history matching and extraction of valuable information on optimum new well locations placement. However, numerical simulation results of Lost Hills were not successful due to the unique characteristics of the diatomite reservoir noted above. Therefore, the current procedures of selecting new well locations are based on the surface patterns and static reservoir properties.

Machine learning (ML) has recently been spotlighted since it does not require specific physical models but can provide good estimations if there is enough data. Features like permeability, oil saturation, and other common reservoir properties also impact on production in diatomite reservoir, but the contribution of each property is not clearly understood. Because of its characteristics of not requiring physical models, ML has strong applicability in Lost Hills of which exact hydrocarbon production mechanisms are not clearly understood.

In this study, a new methodology using Machine Learning was introduced for infill well location selection. This approach led to identification of approximate 550 infill well candidate locations, which were recommended further to the asset development team for execution. The infill well location selection workflow consists of historic data analysis, drainage area estimation, ML model training, and candidate location estimation. Using K-means clustering and statistical means, the characteristics of good producers are analyzed. Then, the drainage area for each well is approximated using Voronoi cells. This allows a relative good estimation of the remaining oil in place and non-draining areas. A support vector machine (SVM) model was trained to rank the locations based on their production capabilities. The new workflow provides more systematic means on new well location selection and enable the asset team to make data driven decisions.
Interpreting Step Rate Tests SRTs in Multi-Layered, Unconsolidated and Stress-Sensitive Formations
Authors: Ershaghi Iraj , Ershaghi Milad A.
Published: April 2018

We studied the applicability of Step Rate Tests (SRTs) for estimation of suitable injection gradients and reviewed various diagnostic plots to examine their relationship with injection rate and pressure. While dealing with multi-layered systems and those consisting of unconsolidated formations and examining the causes of injection increase seen, we identified some shortfalls associated with the SRT procedure. We also examined the force balance of formation response to injection gradients and concluded that formation resistance to water injection changes with time. That means the injection gradient to maintain constant injectivity is affected by the near wellbore conditions and as such, has a dynamic nature and can change with time. For unconsolidated formations, changes in pore pressure may also affect the rock effective permeability which alone can influence the required injection gradients.
Advanced Analysis of Clean-Up and Productivity from Perforated Rocks Using Computational Fluid Dynamics
Authors: Satti Rajani , Zuklic Stephen N. , Bale Derek , Koliha Nils , Fager Andrew , Balasubramanian Gana , Crouse Bernd , Freed David
Published: April 2018

Perforated completions play a crucial role in efficient hydrocarbon recovery as well as long-term well productivity. However, perforating often alters formation permeability around the perforation tunnel, which along with other perforation parameters (penetration, hole size, and shot configuration) significantly impacts near-wellbore pressure drop, and therefore, production. Standard numerical or inflow production models are based on many assumptions involving tunnel geometry and clean-up, debris and damage characteristics. Such an approach often leads to discrepancies between estimated and actual productivity of the tunnel, thereby affecting the overall completion planning through the life-of-the-well.

In recent years, perforation flow laboratories have been leveraged to provide insight into clean-up and productivity mechanisms around perforation tunnels. However, the heterogeneity of the analog cores, challenges with isolating competing effects of debris/clean-up and limited amount of experimental data have led to the advent of computational methods. In contrast to previous studies, the model presented in this work leverages the perforation flow laboratory, micro-CT and conventional CT imaging, and most importantly, an advanced simulation approach to provide an accurate assessment of clean-up techniques and productivity. This full-scale three-dimensional flow model accounts for realistic aspects of tunnel geometry, perforation damage, and blockages/debris that impede the flow.

The simulation based approach facilitated a comprehensive understanding of the competing effects of perforation damage, debris within the tunnel, tunnel tip plugging, and directionality of flow around the tunnel. Whole-field flow visualization including fluid velocities, streamlines, pressure gradients, and most importantly, the flow rates and corresponding productivity ratio are presented and discussed in detail. Further, this study provided insight into quantitative comparisons of influence of debris and the overall effect of underbalance methods on clean-up and productivity. This work therefore enables the implementation of a multi-scale simulation approach as a practical engineering tool that can be used to provide a realistic prediction of downhole productivity as well as evaluating the effects of clean-up techniques. Such insight will eventually provide information that enhances the decision making process of a perforated completion design.
Pattern-Based History Matching for Reservoirs with Complex Geologic Facies
Authors: Golmohammadi A. , Khaninezhad M. R. , Jafarpour B.
Published: April 2018

History matching is performed to obtain reservoir models that reproduce the historical production data while adhering to available prior geologic knowledge and observed static data. In automated history matching workflows, prior models of reservoir properties are continuously updated to match the incoming production history. A challenging problem is to ensure that after applying updates to prior models, the resulting history matched models remain geologically consistent. This is particularly challenging in formations with complex connectivity patterns, e.g., fluvial meandering and curvilinear channels, where preserving the distinct shape and continuity of the underlying geologic features is non-trivial. In this work, we introduce a novel machine learning approach with the aim of preserving the main connectivity patterns of the prior reservoir models during history matching of complex geologic formations. We formulate the history matching problem by defining a feasible set of connectivity patterns that are described by a large number of model realizations. The feasible set encompasses the range of connectivity patterns of the expected geologic objects in the prescribed conceptual model by geologists. A supervised machine learning algorithm is then introduced to learn a mapping operator between any given model and its closest model in the feasible set. For this purpose, a learning dataset, i.e., a set of feature/label pairs, is constructed from the representative samples of the feasible set. The k-Nearest Neighbor (k-NN) classification algorithm is then applied to relate the local connectivity patterns in the feasible set that are closest to the patterns in a proposed model outside the feasible set. The learned mapping operator is invoked during history matching, where the misfit between model-predicted and observed historical production data is minimized while honoring the connectivity in the prior feasible set. The history matching is performed using a two-step alternating directions optimization algorithm, in which the first step implements a gradient-based continuous minimization procedure to decrease the data mismatch objective function while the second step maps the obtained solution from the first step onto the prior feasible set. History matching case studies in channelized reservoirs demonstrate that the proposed supervised learning approach can learn the complex geologic patterns in the feasible set and use them during history matching to preserve the feasible connectivity patterns. The results suggest that the proposed classification and clustering approach can facilitate patter-based history matching problems by learning geologic features from prior models and using them to impose geologic feasibility.
Low Salinity Hot Water Injection with Addition of Nanoparticles for Enhancing Heavy Oil Recovery under Reservoir Conditions
Authors: Ding Yanan , Zheng Sixu , Meng Xiaoyan , Yang Daoyong
Published: April 2018

In this study, a novel technique of low salinity hot water (LSHW) injection with addition of nanoparticles has been developed to examine the synergistic effects of thermal energy, low salinity water (LSW) flooding, and nanoparticles for enhancing heavy oil recovery, while optimizing the operating parameters for such a hybrid enhanced oil recovery (EOR) method. Experimentally, one-dimensional (1D) displacement experiments under different temperatures have been performed, while two types of nanoparticles (i.e., SiO2 and Al2O3) are respectively examined as the additive in the LSW. The performance of LSW injection with and without nanoparticles at various temperatures is evaluated, allowing optimization of the timing to initiate low salinity water injection. The corresponding initial oil saturation, production rate, water cut, and ultimate oil recovery, are continuously monitored and measured under various operating conditions. Compared to conventional water injection, the low salinity water injection is found to effectively improve heavy oil recovery as an EOR technique in the presence of nanoparticles. Also, the addition of nanoparticles into the LSHW can promote synergistic effect of thermal energy, wettability alteration, and reduction of interfacial tension (IFT), which improves water displacement efficiency and thus enhances oil recovery. It has been experimentally demonstrated that such LSHW injection with the addition of nanoparticles can be optimized to greatly improve oil recovery up to 40.2% in heavy oil reservoirs with low energy consumption.
Securing California Gas Supplies by Storage in Mature Fractured Monterey Reservoirs of Offshore California
Authors: Ershaghi Iraj , Paul Donald L. , Kaba Saran
Published: April 2018

In this paper we discuss our studies conducted on two California offshore fields that may be abandoned in near future. The purpose of the study was to examine the feasibility of re-purposing these fields to suitable offshore gas storage by utilizing the reservoir voidage and by using the existing pipeline facilities. These storage sites could offer a significant alternative to the current onshore sites located in highly populated urban areas of California.

Gas storage in certain California offshore fields producing from the fractured Monterey formation could eliminate the potential environmental risks associated with urban onshore storage of gas and prevent incidents such as the October 23, 2015 one in the Aliso Canyon Natural Gas Storage Facility in Los Angeles County. The 100,000 tonnes of methane emitted into the atmosphere resulted in the relocation of thousands of people from the areas proximal to the facility.

Study of the caprock and initial reservoir pressures encountered in these fields shows that a proposed 3000 psi storage pressure is safe for offshore storage purposes. Our computation of voidage caused by more than 3 decades of production shows that on a total basis, under a storage pressure cap of 3000 psi, these two fields together can help in storage of more than 3 TCF of gas. This is about 5 times the existing storage capacity of 0.6 TCF in California. On the long terms basis, the proposed offshore storage fields could provide a secure source of energy for the evolving market of California CNG based transportation, power generation and other consumer needs.
Modeling Pore Compressibility Effects in Unconventional Reservoir Performance Analysis: Application to Bakken Formation
Authors: Eker Erdinc , Uzun Ilkay , Kazemi Hossein
Published: April 2018

Unconventional reservoirs consist of matrix, micro-fractures, and macro-fractures. There is a significant difference between stress-dependent deformation of matrix rock and the fracture-containing reservoir frame. These differences are great enough to affect the long-term production performance of reservoir. Thus, accurate representation and modeling of such diverse characteristics are needed to predict reservoir performance. Changing reservoir pore pressure during production causes decrease in porosity and permeability and deforms the pore geometry. Thus, in mathematical modeling, reduction in pore volume is a rock deformation issue including the ever-changing pore compressibility. Typically, coupled geomechanics and flow simulation models do not account for such details; however, in this paper, we used in-house multi-phase dual-porosity model to show the effect and significance of compaction drive on production performance of a Bakken reservoir.

We have observed that the energy provided by the reservoir compaction increases cumulative fluid production, and numerical models that has constant compressibility values in their transport equations underestimates the cumulative production. Our modeling results indicate that the energy provided by the reservoir compaction increases cumulative fluid production by eleven percent for the Bakken example. Thus, using the results of this paper, we demonstrate the effect of rock elastic properties and stress-dependent porosity and permeability on reservoir long-term performance.
Development and Application of Ensemble Kalman Filter for Efficient Production Data Analysis and Accurate Property Estimation
Authors: Yue Wenting , Wang John Yilin
Published: April 2018

Single-well production data analysis (PDA) is an important subject to understand reservoir productions. This is commonly done with traditional methods/analytical models. But analytical models suffer from limited accuracy and applicability issues due to the way production data is matched, the error involved, and the assumptions that sometimes over simplifying the problem. Therefore, in this work, the authors want to provide an assessment of Ensemble Kalman Filter (EnKF)-based production data analysis model on single-well production.

By assuming homogeneous and isotropic reservoir permeability in a single-layer reservoir, we first formulate the basic EnKF algorithm and link it with single-well reservoir model. Results indicate estimation of skin factor and reservoir permeability present accuracy issues: large error for some cases and uncertainty bounds do not cover true values. Based on our evaluations, we propose the method of increased initial uncertainty bound and over estimating initial observation noise variance to improve the estimation. The method is tested with synthetic models, and results indicate that mean estimate have better match with true value, and the true values fall within a reasonable uncertainty bounds of the ensemble data predictions. Production data from 31 wells in real field are used for further verification. Excellent data matches are obtained with EnKF.

The model in the work could provide a reasonable estimation of reservoir properties for both synthetic and real-field cases. We also show that statistical inconsistency and poor data matches are encountered when matching production data for some extreme cases when permeability of damaged/stimulated zone is drastically different from reservoir permeability. But this issue could be alleviated with the proposed method. The model and method in this study proves to be applicable for real field evaluation.

We present readers with an implementation of EnKF-based in single-well production data analysis to overcome accuracy and applicability issues related with traditional analytical methods. We documented the accuracy and efficiency one could expect when applying this method in both synthetic models and real-field data to evaluate skin factor, drainage area, and permeability. We also proposed and verified a methodology to improve estimation accuracy under some extreme cases when estimation of skin factor possess a problem. This paper could provide a guild to the readers when constructing their own production data analysis model.
Novel and High Performing Wellbore Cleaning Fluids with Surprisingly Flat Viscosity over Time and Different Temperatures
Authors: Pernites Roderick , Padilla Felipe , Clark Jordan , Gonzalez Angel , Fu Diankui
Published: April 2018

Cementing of the casing is critical in well completion and is highly dependent on wellbore cleaning of the drilling mud prior to cement placement. Typically, a water-based intermediate cleaning fluid called spacer is pumped downhole ahead of the cement to carefully displace the drilling mud and clean the well. However, effective well cleaning is challenging and continues to be a problem. Currently, there is no universal spacer formulation that can clean all types of mud. Moreover, maintaining a constant viscosity of the aqueous-based cleaning fluid is extremely difficult to achieve, as it is exposed to a wide temperature disparity from surface to bottom hole circulating temperature (BHCT), creating a challenging scenario to design an effective spacer even with today's displacement softwares.

This paper presents a highly unique and cost-effective wellbore cleaning fluid, which provides superior wellbore cleaning and efficient mud displacement. Unlike many spacer fluids, this new cleaning fluid utilizes a novel material that is not very susceptible to temperature and thus provides a relatively constant viscosity from surface to BHCT, indicating homogeneous and stable suspension of particulates in the fluid at different temperatures. It preserves and extends pumpability, which is useful during prolonged job delays on location or extended residence time inside the wellbore. The innovative material has exceptional physical properties for tightly holding the carrier water while simultaneously upholding the viscosity of the fluid at elevated temperature, translating in a more efficient and realistic fluid removal simulation.

The key novelty and invaluable contribution of this research to the field is the application of a unique material with an exceptional physical property of sustaining flat viscosity of the wellbore cleaning fluid from surface to BHCT, which is highly desirable. To the best of our knowledge, this new material has not been exploited for non-settable spacer fluid applications.
Recent Advances in the Synthesis of Amides via Oxime Rearrangements and its Applications
Authors: Debnath Pradip
Published: April 2018

Background:

Amide bond formation reactions are the most important transformations in
(bio)organic chemistry because of the widespread occurrence of amides in pharmaceuticals, natural products
and biologically active compounds. The Beckmann rearrangement is a well-known method used for the preparation
of secondary amides from ketoximes. But, most of the traditional protocols used for the Beckmann rearrangement
create enormous amount of wastes. Thus, the atom economical synthesis of amides has got high
priority among the chemists. However, under classical Beckmann conditions, aldoximes do not rearrange into
the corresponding primary amides. Indeed, reactions of aldoximes lead to nitriles. In recent years, it has been
demonstrated that the aldoxime rearrangements can be carried out efficiently and selectively with the help of
metal catalysts.

Objective: This review focuses on the recent progress in the amides synthesis via ketoxime and aldoxime rearrangements.
Applications of the rearrangements in the synthesis of heterocycles and natural products are also
covered in this review.

Conclusion:

In the first part of the review, relevant pathways of oxime rearrangements are discussed and it is
shown that several catalytic systems have been developed for the atom-economical synthesis of N-substituted
amides from ketoximes. But similar reactions with aldoximes are, however, more challenging. The advances
reached in the aldoxime rearrangement are also covered in this review. It is revealed that a large variety of
homogeneous and heterogeneous metal catalysts have been developed to affect aldoxime rearrangements.
Formation of the Self-assembled Multilayers Containing the Temperature/ pH Dual-responsive Microgels
Authors: Liu Gang , Liu Chunlin , Chen Yuyuan , Qin Shuai , Yang Suyuan , Wu Dun , Xi Haitao , Cao Zheng
Published: April 2018

Background: Stimuli-responsive microgels have attracted extensive investigations due to their
potential applications in drug delivery, catalysis, and sensor technology. The self-assembled mcirogel
films can contain different functional groups (e.g., -COOH, -NH2, -C=ONH2) to interact with specific
molecules and ions in water, and their study is becoming increasingly important for developing both absorbent
materials and sensor coatings. This paper is aimed to obtain a better understanding of the LbL
multilayer formation of microgels and the branched PEI using the mass sensitive QCM. Additionally the
influence of the temperature and pH on the formation of the microgel films can be achieved.

Methods: The temperature and pH sensitive P(NIPAM-co-AA-co-TMSPMA) microgels were prepared by
surfactant-free emulsion polymerization and confirmed by FT-IR, laser particle size analysis, and SEM.
The obtained microgel and PEI were further used to prepare multilayer thin films by the LbL self-assembly
technique monitored by QCM, and their morphology and hydrophilic properties were determined by AFM
and water contact angle measurements.

Results: The thermosensitive and pH sensitive P(NIPAM-co-AA-co-TMSPMA) microgels were prepared
by surfactant-free emulsion polymerization. The size and swelling properties of the microgels prepared are
highly dependent on the preparation conditions such as the AA and crosslinker content, and microgels
showed good temperature and pH responsive properties. SEM images showed that microgels dispersed
evenly on the substrate and had a uniform particle size distribution, which was consistent with the light particle
size analysis results. Furthermore, multilayer films composed of the negatively charged microgels and
the positively charged PEI have been built up by a facile LbL assembly method and the influence of the
deposition conditions on their formation was monitored in real time by QCM. Compared to the temperature
of 25 °C, the high temperature of 35°C above the phase transition temperature leads to the more adsorbed
mass of microgels on the gold surface of QCM sensors. The absorbed mass values at the deposition
pH 7 and 10 are 9.82 and 7.28 µg cm-2, respectively, which are much higher than 1.51 µg cm-2 of the layers
deposited at pH 4. The water contact angle and AFM both confirmed the wettability properties and morphology
of multilayers on the gold surface of QCM sensors.

Conclusion: The formation of the multilayer films on the gold surface by the layer-by-layer deposition
technique of the negatively charged microgels and the oppositely charged PEI can be achieved. The
controllable multilayer formation can be attributed to the size difference, changes in the hydrophilic
property and surface charge density of microgels responsive to the external temperature and pH.
Comparison of Heart Rate Variability Parameters in Patients with Cardiovascular Diseases and Concomitant Phenomenon of Heart Rate Turbulence wih the Indicators of Apparently Healthy Individuals
Authors: Vytryhovskiy A I
Published: April 2018

The objective of the research was to develop new approaches to the prognosis, prevention and treatment of complications in patients at high and very high total cardiovascular risk based on the assessment of the state and effect on heart rate variability and heart rate turbulence.Materials and methods. There were examined 319 patients; they underwent a 24-hour monitoring of their heart rate variability and heart rate turbulence. All the patients were divided into three groups: Group 1 included patients with coronary heart disease (post-infarction cardiosclerosis) without concomitant risk factors such as smoking, obesity, metabolic syndrome; Group 2 consisted of patients smoking tobacco for more than 2 years; Group 3 included patients with metabolic syndrome and arterial hypertension; the control group.Results. In patients with coronary heart disease and concomitant phenomenon of heart rate turbulence, the activity of the parasympathetic nervous system was significantly higher in the active period of the day, while the passive period of the day was associated with the elevated level of stress. Due to this, among patients of this group, there was a decrease in the tension value of the total body regulation in the passive period of the day, while in healthy individuals, its increase was observed. In patients at high and very high cardiovascular risk according to the SCORE charts with the phenomenon of heart rate turbulence, the stress index was significantly higher throughout the day as compared to apparently healthy individuals. In patients at high cardiovascular risk and concomitant phenomenon of heart rate turbulence, the parameters of heart rate turbulence acceleration were significantly higher as compared to those of apparently healthy individuals.Conclusions. In patients at high and very high cardiovascular risk according to the SCORE charts with coronary heart disease and concomitant phenomenon of heart rate turbulence, the occurrence of ventricular extrasystole had a vagal nature; they were characterized by a higher level of stress in the passive period of the day as compared to the active one.
ALLEN BUCKNER KANAVELFOUNDER OF HAND SURGERY
Authors: Egiazaryan K. A. , Magdiev D. A.
Published: April 2018

Allen Bakner Kanavela's biography - the surgeon who has brought the invaluable contribution of a world scale in development of the general surgery and of hand surgery is presented.
EVALUATION OF INFLAMMATORY CHANGES IN JOINTS AT PATIENTS WITH HEMOPHILIA ACCOMPANIED RECURRENT HEMARTHROSIS
Authors: Davydkin I. L. , Kosyakova Y. A. , Lartsev Y. V. , Kapishnikov A. V.
Published: April 2018

Objective: to search for new diagnostic approaches for estimating the prevalence of posthemorrhagic phase of inflammation in the joints of patients with hemophilia accompanied recurrent hemarthrosis. Using the method of computerized infrared thermography measured the temperature above the knee, ankle and lower leg. Analysis of the data held with a specially developed algorithm that forms the basis of a computer program for computer (2009). It is established that with increasing temperature over the joint at high risk of recurrence monthly hemarthrosis. If the joint hemarthrosis was not, then an increase in temperature may indicate a latent flowing inflammation. Assessing the prevalence of inflammation in the joints of patients with hemophilia has prognostic value: widespread inflammation is characterized by continuous recurrent course, for a limited - monthly recurrent hemarthrosis, in the absence of inflammation in the joint, as evidenced by normal or low-grade fever, recurrent hemarthrosis are likely rare.
REPLACEMENT OF PROXIMAL INTERPHALANGEAL JOINTS IN HAMMER TOE DEFORMITY
Authors: Petrosyan A. S. , Zagorodniy N. V. , Protsko V. G. , Sultanov E. M. , Khamokov Z. K. , Butaev B. G. , Zakharyan N. G.
Published: April 2018

Objective: to assess the results of Hammertoe Implant Procedure (HIP) in the treatment of hammer toes deformation. 28 operations were carried out in 16 patients aged 26 to 58 years with stage II-III (according to the classification of MI Kuslik) of hammer toes from September 2009 to March 2011. In 50% of them surgeries were performed on one foot, in the second half - on two feet. Mean duration of follow-up was 12.4 months, range 6-21. Results: evaluation of the results was carried out by scale of AOFAS. A significant improvement was noted after HIP: in average score before surgery - 47, in the postoperative period - 92. In evaluating the average preoperative pain score was 24.3, postoperative - 36.0 (complete absence of pain is estimated to be 40 points). Improving the function of the foot with an average of 19 before surgery after surgery reached 41 points, while the position of the fingers (the alignment of the foot and toes) is changed from the average value of 2.4 to 12.4 after surgery. Conclusion. Analysis of results showed the effectiveness of the HIP method in the treatment of hammertoe 2-3 fingers. HIP has allowed to achieve good functional and cosmetic results in early and the follow-up postoperative period. In our view, HIP with complex deformations forefoot can be used as an adjunct to other types of reconstructive surgery on the anterior part of the foot, and cases with recurrent strains hammer toes after surgery, HIP can be operation of choice.
ANALYSIS OF LONG-TERM RESULTS OF SHOULDER ARTHROPLASTY
Authors: Nenashev D. V. , Varfolomeev A. P. , Maykov S. V.
Published: April 2018

The retrospective analysis of 97 shoulder arthroplasties during 1998 to 2009 was performed. The hemiarthroplasty were fulfilled in 92 patients and total shoulder replacement in 5 patients. Total rate good and satisfactory results consists 32,0%, poor results - 68,0% (66 patients, include 5 patients with total shoulder arthroplasty). The lower level of good results was revealed in patients with chronic fractures and fracture-dislocations of shoulder. It related with changes bones of shoulder and muscles of shoulder (rotator cuff). In the studied group of patients there was no proper pre-operative diagnostics of the rotator cuff, articular surface of the scapula, which shows the need for careful preoperative examination to determine the indications for shoulder arthroplasty and select the type of prosthesis. Unsatisfactory results of total arthroplasty related to screw migration (in case of the transacromion approach) and to the development of subacromial impingement. The conclusion about the need to narrow the indications for use of the scapular component «Ortho-P». The authors showed preference to cemented implants without a metal base. It is necessary to introduce in practice the anatomic implants of the third generation allowing the fullest play the anatomy and biomechanics of the shoulder joint.
LONG-TERM RESULTS OF CRYOSURGICAL TREATMENT OF BONE TUMOR-LIKE LESIONS
Authors: Dianov S. V. , Tarasov A. N. , Mochalov A. P.
Published: April 2018

In order to optimize surgical intervention the results of surgical treatment of 324 patients with tumor-like lesions of bone were studied. Study group comprised 211 people who were executed cryosurgical intervention. In 113 patients (control group) a similar intervention was performed, but without the cryosurgical exposure. In the study group the subjective and objective assessment of outcome of treatment was significantly different (at χ2 = 9,5 p
TALONAVICULAR JOINT ARTHRODESIS AND MEDIAL DISPLACEMENT CALCANEAL OSTEOTOMY FOR TREATMENT OF PATIENTS WITH PLANOVALGUS DEFORMITY
Authors: Dubovik G. O. , Zagorodniy N. V. , Protsko V. G. , Butaev B. G. , Tamoev S. K.
Published: April 2018

The aim of this study was to assess the results of talonavicular joint arthrodesis and medial displacement calcaneal osteotomy for surgical correction of pes planovalgus. Fourteenth patients with a pes planovalgus deformity were underwent surgery from February 2008 to December 2011. The mean age was 45,5. In 90% of cases, operations were performed on one foot, and 10% of cases at two feet. All patients were assessed before the operation with the scale of the American Orthopaedic Foot and Ankle Society (AOFAS). According to the AOFAS scale, the average improvement was 41 before the operation had reached values of 84.2 after the operation. Radiography showed an average decrease in the angle of the longitudinal arch from 12 and an average decrease in the angle of deviation between the vehicle collision and the calcaneus to 38°, increasing the height of a set of 5 mm. This combination of procedures allows greater correction and stability than either procedure performed alone, and provides a viable alternative to triple arthrodesis.
TRAUMATISM AND ORTHOPEDIC DISEASES INCIDENCE IN ADULTS OF ST. PETERSBURG IN 2008-2011 AND ACTIVITY OF TRAUMA AND ORTHOPEDIC CARE SYSTEM
Authors: Tikhilov R. M. , Vorontsova T. N. , Cherniy A. G. , Luchaninov S. S.
Published: April 2018

The article deals with basic findings derived from annual investigation, held by Coordination-methodic Center specialized in “orthopedics and traumatology”. The analysis of dynamics of main indices of incidence of trauma and musculoskeletal diseases in adult population was based upon official findings of federal statistic monitoring of condition and work of specialized medical service. The evaluation of structure, dynamics and work of the hospital and out-patient service was made in compare with incidence dynamics of trauma and musculoskeletal diseases. Generally Saint-Petersburg characterized with high level of traumatism of population with tendency to decreasing, big part of severe skeletal injuries of population, increasing of number of patients with chronic diseases of locomotor system, big part of yang and middle aged patients with temporary lost of possibility to work because of injuries, high level of mortality (with prevalence of men) and tendency to decreasing. Trends of processes of traumatology and orthopedic care system reflects increasing of volume of specialized trauma service for city population as in ambulatory as in hospital links, increasing of intensity of using of traumatology and orthopedic beds in city hospitals, decreasing of deaths caused of injuries in city hospitals, increasing of number of surgical interventions of locomotor system and decreasing of postoperative hospital mortality.
TREATMENT OF THE LOW LIMB DEFORMITIES IN YOUNG CHILDREN WITH ARTHROGRYPOSIS (REVIEW)
Authors: Baindurashvili A. G. , Derevyanko D. V. , Agranovich O. E.
Published: April 2018

The review of domestic and foreign literature on a problem of treatment of the low limb deformities in young children with arthrogryposis is revealed in the article. Questions of medical tactics and its peculiarities in one and both sided congenital hip dislocation are touched upon. Basic worldwide tends of hip surgery development and effectiveness of different methods in arthrogriposis are revealed. Views of domestic and foreign authors on a problem of knee joint contractures treatment are represented and different conservative and surgical methods according to severity of deformities are described. Results of clubfoot treatment of different authors are shown in the article. Ponseti method and its possibilities for clubfoot correction in arthrogryposis are specified. Questions of treatment of planovalgus deformities are also touched upon as well as problems of orthotic supply in accordance with type of the deformities and its combination.
THE ANALYSIS OF MORPHOFUNCTIONAL CONDITION OF THE UPPER LIMB MUSCLES IN TREATMENT OF PATIENTS WITH POSTTRAUMATIC ELBOW FLEXION-AND-EXTENSION CONTRACTURES
Authors: Grebenyuk L. A. , Soldatov Y. P.
Published: April 2018

The aim of the work was to study the echography visualization-based structural features of muscles and the wrist radial flexors for surgical treatment of 56 patients with the elbow flexion-and-extension contractures. The result of surgical treatment in the main group of patients consisted in the increase of the elbow extension angle. Muscle pattern was similar to a typical, normal ultrasound image. The most characteristic feature was a significant decrease in the muscle belly thickness. The thickness of fore-arm flexor muscular layer was 29,2% decreased for the brachium injured amounting to 16.5 ± 4.7 mm (P ≤ 0.05), and that for the intact segment - to 23.3 ± 2.6 mm. In the immediate periods after treatment the signs of atrophy remained. It manifested by the significant decrease of the anterior muscle group thickness with regard to the intact segment values. The index of the echo intensity of m. biceps brachii in operated limb increased by 53.7% compared to preoperative values, reaching 22.8 ± 2.1 conv. u (P 0.05). Before the treatment in patients aged 8-13 years the relative strength of the forearm muscles was reduced by 12% compared with those on the contralateral limb (P
THE SUBSTANTIATION OF EARLY SURGICAL TREATMENT OF CONGENITAL PATELLA DISLOCATION
Authors: Tenilin N. A. , Bogosyan A. B. , Vvedensky P. S. , Vlasov M. V.
Published: April 2018

The present work is based on the results of congenital patella dislocation treatment in patients aged from 4 months to 18 years old (average 10,6±0,7 years). The results were estimated in the period ranged from 1 to 40 years (average 15,1±2,1 years). The new classification of congenital patella dislocations was based on the gait biomechanical parameters. The necessity of early surgical treatment of congenital patella dislocation has been proved.
REVISION SURGERY IN PATIENTS WITH SCOLIOSIS OPERATED WITH PLATE ENDOCORRECTORS
Authors: Kolesov S. V. , Baklanov A. N. , Shavyrin I. A. , Kudryakov S. A.
Published: April 2018

The authors presented 19 clinical observations of patients undergoing surgery at the primary idiopathic scoliosis using plate endocorrectors. The following characteristics were determined: the fixation of posterior elements of the spine there is no possibility of adequate derotation scoliotic vertebrae arc and require extensive fixation of the spine (Th2-L4), significantly reducing the functional activity of the patients. The lack of the fusion is accompanied by system micromotion, causes the instability of the upper pole of the metal construction and provokes the formation of a fistula. The presence of fibrous scar, and later - bone block, doesn’t allow to realize the lengthening effect during the patient’s growth and causes the development of Crankshaft-phenomenon, the correction of which requires a long, traumatic, multi-stage surgery.
SUBSTANTIATION OF THE NEW METHOD OF CLOSED REDUCTION OF FRACTURE CALCANEUS
Authors: Kupitman M. E. , Atmansky I. A. , Chemikov M. K. , Maminov D. V. , Gashev A. A. , Zubkov M. A. , Semenov A. A.
Published: April 2018

The authors presented the results of analysis of surgical treatment 52 patients with calcaneal fractures in the trauma department of Magnitogorsk city hospital N 3 from 2007 to 2009. On the basis of these results a new classification of calcaneal fractures was created, which determined the tactics of closed reduction. The author’s method of minimally invasive reposition in patients with calcaneal fractures n is described. The results of applying this technique in 25 patients were evaluated. According to the authors, the closed reduction technique is simple and can be applied in any trauma department in the presence of X-ray control. This technique has a very good cosmetic results and the small number of postoperative complications.