Gazovaya promyshlennost’ № 05 2018

The extraction and processing of raw materials with a high content of hydrogen sulphide (about 26 %) is the most important feature of the Astrakhan gas condensate field with regard to the specifics of the used technologies and the company's environmental impact, as well as the high potential hazard of production for personnel and public. One of the first in Russia information management system for monitoring, preventing and eliminating emergencies has been scientifically substantiated and designed to ensure industrial safety of the field. The system includes modern high-tech measuring complexes, communication equipment, data management and distribution capabilities operating within a single system-integrated approach. The automated management and implementation of these tasks are provided with the help of newly created and upgraded subsystems of the enterprise. The system of industrial and environmental monitoring carries out continuous monitoring, signals the excess of the established threshold levels and the maximum permissible concentrations of harmful chemicals. The notification system promptly notifies management, personnel and public about the situation at the facility and emergency situations. The subsystem of satellite navigation and vehicle movement control of the emergency service allows to track the current coordinates, direction and speed of vehicles in real time. The subsystem of technological video monitoring performs visual monitoring of the monitoring systems, the work of rescuers, compliance with the requirements for the release of excess pressure in the wells. The telemetry subsystem of rescue equipment performs centralized monitoring of the air container status and the mobility of personnel of rescue squads. The integrated communication and data transmission network ensures the necessary operativity of data processing, decision making and control over their implementation. The implemented technical solutions fully comply with the regulatory requirements in the field of organization and provision of industrial safety at hazardous production facilities and exceed the existing requirements for a number of indicators and implemented additional functions.

Creation of a reliable support as a main functional part of a well, consisting of casing pipes and cement sheath, is of particular importance during well construction. The problem of improving the quality of wells stabilization which depends on many natural, technical and technological factors is constantly becoming more complex as it moves to greater depths. If the wellbore enters a geological section with complex mining and geological characteristics, it becomes necessary to stabilize the zones with abnormally high formation pressures under high temperatures. The complications, caused by gas flow into the wellbore, often occur in the process of drilling-in the gas-oil-water-saturated reservoirs of a cracked type. The article considers the results of research of gas manifestations causes during the stabilization of deep exploratory wells in complicated mining and geological conditions. The study reveals the reasons for the gas surge upward from the lower gas-bearing formation when drilling out the casing shoe of a tail pipe that is provoked by the high hydrostatic pressure of the drilling mud. The results of field work, the attempts to eliminate gas manifestations by means of a stepwise increase in mud density to a maximum value and a change in the flushing scheme, are described. The possibility of estimating the prevention of gas escape through the hydrated cement behind a tail pipe using the calculation method for the example of a specific deep well, as well as the distribution of pressures and possible gas manifestations behind the casing string are considered. A refined mechanism for calculating the limiting pressure in the well is given which makes it possible to draw conclusions and develop proposals on the technological parameters of the drilling process aimed at preventing gas manifestations during stabilization of wells.

The conditions of convective currents rising from mantle to the surface and forming the topographic uplifts and confined zones of oil and gas accumulation in the northwest of the Siberian craton (Russian Federation) are determined. It is noted for the first time that data of the seismic profiling with nuclear explosions is an evidence of the subduction of the West Siberian plate under the Siberian craton in the Late Mesozoic. The order of the location of the relief anomalies at the northwestern part of the Siberian craton is also the evidence of that: the megaswells are located to the west of the megadepressions, and the chain of arched uplifts is to the east of them. In the case of the formation of these topographic anomalies on the West Siberian plate and the subsequent thrust onto the Siberian craton, the order of the arrangement of megaswells, megadepressions, and the chain of arched uplifts would be inverse to the observed one. The stability of the overthrust motion occurring under the lithosphere in the zone of plate collision is studied. It is shown that the spatial distribution of the relief anomalies associated with sub-lithospheric convective currents in the mantle corresponds to the average velocity of collision of the Siberian craton with the West Siberian plate 0.06 m/year. Quite high effective viscosity coefficient in the mantle wedge (4.2·1020 Pa·s) is an evidence of absence of the asthenosphere in this region.

The article discusses the features and approaches to the development of the Murmanskoe gas field in the Barents Sea. The estimation of production capability is made, the approaches to formation of well stock are offered taking into account a complex geological structure of a deposit and the restrictions imposed by marine conditions in the Arctic. The article gives suggestions on the arrangement of the production field, including the subsea and above-water parts, when subsea completion of the wells is partially applied. The estimations of development parameters for the full development of the production field are presented. The possibilities of transportation of gas to the land with an estimation of a diameter of the gas pipeline are considered taking into account the relief of the sea bottom. In general, it was concluded that existing technologies allow the development of the Murmanskoe field, but the feasibility of development depends on the gas market state and the economic assessment. The downsized version of the field development to meet the power supply needs of Murmanskoe and Severomorsk as the main heat consumers on the Kola Peninsula is discussed. This version requires significantly less capital and operating costs and can be effective against the existing alternative based on coal and fuel oil. This version of development may be provided by subsea production field. It will require almost an order less wells, the project can provide these cities through an ultra-high pressure subsea pipeline without intermediate compression of gas for many years. Simultaneously, this version of development can be considered as an experimental and industrial one and increase the study of this complex field. It is concluded that the Murmanskoe gas field may be the first production zone in the Barents Sea in the presence of a gas market channels and a positive economic assessment.

Gazprom PJSC has several licenses for offshore areas located in the waters of the continental shelf of the Sea of Okhotsk with sea depths from 100 m and more, which are located at a considerable distance from the coastline. Compared with the shelf regions of the Sakhalin island, where hydrocarbon fields are currently being developed, the water areas are certainly characterized by a number of distinctive features of natural conditions and should be referred to as insufficiently studied ones, according to formal criteria for determining the degree of territory study. In particular, a greater intensity of wave and flow velocities, more severe and, possibly, specific ice conditions can be expected here. The article presents results of studies performed within the framework of marine expeditions during the ice-free (autumn of 2015) and the ice (April, 2016) seasons. The studies were carried out on behalf of Gazprom PJSC. As one of the main results of the first expedition, the high velocities of current were recorded with the help of autonomous hydrological stations, both in the near-surface (up to 2.7 m/s) and the bottom (up to 0.4 m/s at a depth of 170 m) water layers. The winter expedition was carried out with icebreaking ship. The ice drift characteristics were obtained with the help of drift-mounted buoy-markers, a lot of data on the morphometric structure of the hummocky formations is collected. The digital relief models of the lower and upper surfaces of the surveyed ice formations were developed, the air drone was used for survey. The average value of the total thickness of ice exceeded 3.5 m for 12 ice formations. The wide distribution of ice formations with a relatively flat surface was revealed – up to 5–6 layers of ice with a thickness of 0.5–0.6 m each. If the typical nature of such ice formations is confirmed in subsequent studies for this area, then they can be considered as one of the defining design scenarios in the design of offshore platforms.

Transportation of natural gas through the system of main pipelines requires to place the process piping of compressors of compressor plants above the ground. Open areas of the process piping are characterized by high power of emitted noise, which causes harmful working conditions for maintenance personnel and noise load on ecological systems around gas transportation enterprises. Reducing the noise intensity of the technological piping of the compressors can be accomplished in two ways: by installing silencers inside the gas flow or by installing special soundproof structures on the surface of the pipeline. Special soundproof coatings for pipelines are mainly used at present. Usually, pipelines are made of cylindrical pipes with a shallow wall thickness. Studies of the soundproofing capacity of the walls have shown that it does not follow the law of mass and depends in different ways on the frequency of sound (depending on the type of excitation). The majority of ground connection piping of gas compressor units of compressor stations of Gazprom PJSC are equipped with heat and noise insulation coatings, the purpose of which is to protect the station personnel from acoustic and thermal effects emitted by pipelines. Experts from Gazprom VNIIGAZ LLC analyzed research on sound insulation of pipelines conducted by the Research Institute of Building Physics of the Russian Academy of Architecture and Construction Sciences. The article discusses the results of tests of a large number of soundproofing structures and gives recommendations for the application of optimal design. An essential advantage in the insulation of sound-active pipelines with elastomeric materials is the possibility to simulate sound-insulating structures in accordance with the assigned acoustic task. The disadvantages of rubber-based elastomeric materials include their insufficient fire resistance (G1 class), wherefore they should be used with a non-combustible coating of the NG class.

The main tasks of the gas distribution and gas consumption systems operation are safe and uninterrupted supply of gas to consumers, reduction of labor costs and operating costs, and increase of economic efficiency. The problem of reliability of the gas-distribution and gas-supply systems during welding operations arises in this connection. The work on comprehensive diagnostic testing of the gas-distribution systems and the industrial safety expertise is regulated by the current regulatory documentation. Compliance with the requirements of regulatory documentation allows to classify and identify the main types of defects, which reduce reliability and directly affect the further operation of gas pipelines. Non-destructive testing, including the X-ray testing, is applied for identification of defects during the gas pipeline construction. The purpose of this work is to determine the optimal modes of X-ray testing using the X-ray pulse apparatus for detecting defects in welded joints of steel gas pipelines of the gas-distribution and gas-supply systems. The article presents the method of X-ray testing and defines the main criteria for the detection of defects in welded joints. The calculation and determination of optimal modes of X-ray testing using the X-ray pulse apparatus on steel pipes of large and small diameters are performed. The main schemes for control of welded joints depending on the pipe diameter are selected, the number of exposures is determined. The calculation of the focal distance for pipe diameters from 57 to 700 mm is carried out, and the exposure time is determined. The X-ray images and the X-ray film types are analyzed to meet the criteria for the detection of defects in welded joints. The X-ray testing modes for specific pipe diameters of gas pipeline are given.

The article presents the residual life assessment of defective pipes of the main gas pipelines of Gazprom PJSC. The paper discusses one of the ways to improve reliability of the main gas pipelines through pre-start hydraulic testing by stress-test method, which was used to put the Blue Stream, Yamal – Europe, North Districts of Tumen Region – Torzhok, and the Nord Stream main gas pipelines into operation. The results of a comparison of the theoretical approaches and practical application of the hydraulic testing by the stress-test method are considered to ensure the quality of both new and used gas pipelines. Residual life assessment of defective pipes of the Yamburg – Yelets main gas pipeline is performed at the section between the Davydovskaya and Pervomayskaya compressor stations. The results of selection of pipe sections been in operation are described. Composition and properties of defects, such as corrosion, longitudinal crack zones, longitudinal-seam anomalies are presented. Details of the creation of a special test bench for testing the given technology are provided, along with the data for the completion of a main equipment allowing hydraulic pressure testing without using expensive equipment. Sequence of calculations by a special testing technique using a stress-test method is presented, and a bench testing procedure for confirmation of estimated pressure of destruction of one of the defective pipes is introduced. Recommendations are given for performing fatigue life predictions for residual life assessment of defective pipes.

In the oil and gas industry, the maintenance and repair system is aimed at restoring and maintaining equipment for mining, transportation and storage. Planning and control are one of the key functions of this system. The implementation of these functions is possible with sufficient support of oil and gas companies with regulatory and technical documentation and pricing documentation for maintenance and repair of technological and auxiliary equipment, as well as their own databases of indicators. The lack of systematic approaches in the development of documents and indicators does not allow to take into account the peculiar features and characteristics of maintenance and repair of technological equipment of corporations, as well as the use of outdated documents and indicators negatively affects the quality of cost planning and determination of cost of works. It is important to design a database of indicators as a set of information that reflects the state of objects and equipment, their properties and basic characteristics, regulatory and actual data of maintenance and repair. The effectiveness of planning and management of these works depends from the validity, accuracy and reliability of indicators. The main characteristics of the indicators are transparency, validity, continuity, remove duplication, optimality. The article presents the main approaches and stages of the development and formation of a single database of indicators for maintenance and repair of equipment used in the oil and gas industry. The general examples of frameworks and datablocks for ensuring its functioning, the suggestions on the composition of maintenance and repair indicators and criteria for their evaluation are given. The enlarged matrix of the support of normative indicators of types and directions of activity is proposed as an output framework of the database Application of the proposed approaches will not only ensure transparency, accuracy and validity of maintenance and repair indicators, but also implement integrated process management.

The review of international, European and American normative documents for testing to determine the limits of fire resistance of building structures in the simulation of the hydrocarbon fire is presented. The regulatory requirements for ship structures in the design of ships and offshore fixed platforms are analyzed. It is determined that unambiguous requirements to the fire resistance limits of structures to the effects of the hydrocarbon fire are present only for offshore fixed platforms. Disagreements in the normative documents regulating the appropriate test methodology for platform structures are revealed. Fireproofing for ship and building structures for samples tested under the hydrocarbon fire are analyzed. The requirements for design solutions, materials and technologies for the design of marine transport facilities, floating drilling rigs and berthing facilities are shown. The certificates for ship fire-prevention designs are given in the tables. The main principles of normative documents of the leading foreign companies of the oil and gas complex in the field of fire protection of structures are considered. It is found that the use of fireproofing in the conditions of the hydrocarbon fire is regulated abroad by their own industry standards, while Russian manufacturers conduct tests of the produced fireproofing voluntarily, according to the procedures given in various foreign regulatory documents. It is concluded that the development of domestic regulatory database, regulating the requirements for building structures in conditions of possible development of the hydrocarbon fire, and the design of Russian methods for testing structures under the conditions of the hydrocarbon fire are necessary.

The tasks of ensuring the reliability of the main gas pipelines in the cryolithozone are very relevant at present time. Various incidents associated with changes in the mechanical properties of metal of the pipes, loss of ductility at low temperatures, and changes in spatial positions relative to the proper locations in permafrost, take place increasingly frequently. The nature of the damage to the main gas pipelines varies by different regions. In the regions with high air humidity and soils frozen to a shallow depth in winter, the points of the beginning of defect formation occur on the surface of the pipes (corrosion). In the regions of the cryolithozone distribution, the onset of defect formation is in the body of the pipe wall and increase of these defects leads to more catastrophic consequences than in other regions of the country. The article considers one of the sections of the linear main gas pipeline, where an incident occurred as a result of frost heave of the pipeline. The main cause of the frost heave is the ever-changing relief of this site as a result of periodic thawing of permafrost. The current regulatory documents for the construction of main gas pipelines provide calculations mainly based on the general rules of structural mechanics. Thus, a project organization may not sufficiently consider best practices in scientific research in the field of cold resistance and operation of main gas pipelines in the conditions of cryolithozone and extremely low temperatures.

The reliability of pipelines in the complex climatic and geotechnical conditions of Western Siberia is mainly determined by the ability of the pipeline structure to resist the adverse dynamics of repeated annually hydrogeological and geocryological processes. One of the most dangerous processes is frost heaving, which can develop great efforts and leads to tight bends of short sections in the vertical plane. Frost heaving has the greatest influence to the warm and cold pipelines, because the pumped product is a source of cold. The designed systems of engineering protection against frost heaving have insufficient efficiency at the areas of non-continuous distribution of permafrost soils, that is confirmed by the numerous accidents occurring both on the main and on the field gas and condensate pipelines annually. It demonstrates the urgency of the problem of improving the reliability of pipelines in heaving soils. The authors proposed to divide the methods of engineering protection into two groups: the first group allows eliminating the frost heaving; the second group allows reducing the force effects from heaving soils. The paper presents the numerical study of various methods of engineering protection of the first group and conclusions on their effectiveness in the conditions of flooded soils on the flat territories of Western Siberia, taking into account the experience of pipeline operation. Numerical studies showed high efficiency of heating and waterproofing for engineering protection of pipelines from heaving soils. Electrical heating can completely eliminate a frost heaving, because the soil stops to freeze. The optimal position of the membrane was determined for waterproofing. This position reduces frost heaving with maximal efficiency.

The experience of development of biological preparation on the basis of rhizobacteria and nitrogen-fixing hydrocarbon oxidizing bacteria for use in restoration and clean-up of contaminated and disturbed lands of the oil and gas complex facilities is described. The advantage of using a consortium of strains over the one-component biological preparations is experimentally proved. The experiments were performed with two-component solutions of strains for assessment of the effect of cultures of microorganisms on the vegetative processes of plants, for determination of optimum ratios of cultures in solutions and dependence on temperature factors. Three ratios of cultures (1: 2, 2:1, and 1:1) are considered. The effectiveness of each solution was determined separately. The studies of two-component solutions were carried out at three temperature regimes (10, 25 and 35 °C) with the object of modeling the potentially possible climatic conditions for the biological preparation use on the oil and gas complex facilities. The results of laboratory tests of the developed biological preparation are presented. The strains characterized by sufficient destructive activity to hydrocarbons were selected in the course of laboratory experiments, that opens prospects for their use during the biological stage of restoration of contaminated lands of the oil and gas complex facilities. The performed experiments confirmed the ability of selected strains to develop at temperature of 7 °C and the possibility of their use in remedial action of hydrocarbon contamination of soil in the regions with a short vegetation period. The use of biological preparation on the basis of a two-component solution is shown to allow achieving the decrease in the hydrocarbon contamination concentration by 36 % in 30 days. The experiments showed the positive dynamics of influence of biological preparation on the soil, that gives grounds for approbation of the developed biological preparation in the field, directly at the the oil and gas complex facilities in various climatic zones of the Russian Federation.