Tag Archives: gas
Detonation is a self-sustaining process that exists in chemically active media. The possibility of propagation of the detonation wave is provided by energy release in a medium that compensates the energy costs of the detonation wave for an irreversible transformation of the medium. The phenomenon of detonation in bubble media was found in .
A wave of bubble detonation exists in chemically active bubbling media. Such systems include – «chemically inactive liquid – mixture of bubbles of chemically active gas»  and «liquid fuel – bubbles of gaseous oxidizer» . Possessing features common to all detonation waves (this self-sustaining, autowave stationary process), the wave of «bubble» detonation has specific features that manifest itself in the structure, properties, and mechanism of propagation. Studies of detonation waves in bubbling media are devoted to [4-16].
The possibility of initiating a detonation from a bubble mixture with an explosive gas into the region of the explosive gas above the bubble liquid is shown in . In experiments, bubble detonation was excited by the explosion of a wire in a bubble medium. The destruction of the boundary of a bubble medium is considered when a bubble detonation wave is reflected from it. The experiments were carried out at different distances between the wire and the boundary of the gas-liquid medium, this distance was reduced to 1 cm when a gas explosion occurred by the hot products from the explosion of the wire. The probability of transmission of the detonation process from the gas-liquid medium to the volume of the explosive gas is determined as a function of the distance from the wire to the boundary of the gas-liquid medium. Preliminary analysis indicates that a detonation wave refracted from the bubble liquid into the region of the explosive gas can not initiate detonation in the gas region, since from the free surface, the detonation wave is reflected both from the free surface and the compression wave passing into the region of the explosive gas has a small amplitude that is insufficient to initiate detonation. The purpose of this paper is to investigate the process of reflection of detonation waves from a free surface.
Detonation waves exist in a variety of environments. Despite the differences in the structure and physical-chemical properties of systems detonation wave in all environments share common characteristics: detonation – a self-sustaining process. This fact is a manifestation common to all systems, properties are chemically active environment. It is the presence of energy in the environment provides the possibility of the existence of waves of detonation.
Detonation in bubble media is a unique phenomenon: a bubble detonation wave can exist in systems with extremely low energy content, mass the caloric content of chemically active bubble system by six orders of magnitude smaller than conventional solid or liquid explosives. The detonation in bubble environments, possessing common to all of the detonation wave characteristics, has a number of features, manifested in the structure, properties and mechanism of spreading [1-7].
Detonation – dissipative process: the possibility of propagation of detonation waves is provided by the energy deposition in the environment. In bubble media type» chemically inactive liquid–gas bubbles chemically active «substance capable of energy release are in the gas phase (gas bubbles). If you change the initial pressure with a given volume concentration of the gas phase mass concentration of gas and therefore the energy content of the system change. Thus, the initial pressure of the bubble environment is an important parameter affecting characteristics and the possibility of existence of detonation waves.
The study of detonation waves in bubbly liquids related to the issues of explosion safety of such systems. From experiments  it is known that the initial pressure significantly affects the speed and amplitude of waves of bubble detonation. Therefore, it is necessary to study the influence of initial pressure in the bubble on the system characteristics (speed, amplitude, amplitude and length of the original signal capable to initiate a blast wave in a bubbly liquid) detonation waves.
The article reveals the effect of new oil and natural gas classification establishment, which came into force on January 1st, 2016, as well as its positive and negative aspects. The classification is adjusted to the international standards of Society of Petroleum Engineers (SPE) and the USA Security and Exchange Commission (SEC). Its basic feature is the priority of economic efficiency. The practical value lies in the provision of state interests at reserves cost evaluation, which builds the major part of national wealth, as well as in the consideration of tax incentives eligibility. Introduction of such classification should result in the increase of Russian deposits investment potential as well as in the economic efficiency of hydrocarbon reserves production under the conditions of qualitative and quantitative mineral-resource base characteristics deterioration. However, the geological (reservoir type, reserve calculation algorithm, degree of reservoir structure complexity, reserves division), technological (well spacing, oil recovery factor), organizational (computer modeling) and administrative (schedule reduction and special technical and economic features of project approval) aspects could negatively reflect on small subsurface users developing one or several small and middle-sized deposits. Considering the reviewed issues, the author suggests the additional correction of legal and regulatory framework with the aim to eliminate the abovementioned consequences and to support the financial position of small subsurface users.
Currently in the Timan-Pechora oil and gas province (TPОGP) opened about 100 hydrocarbon deposits in the upper Devonian complex. The discovery of large oil deposits in the 80-ies of the 20th century in the upper Devonian complex on Kharyaga and Pisarska fields was the incentive to increase exploration for these deposits. Search works on upper Devonian complex were isolated in a separate direction.
This paper presents a brief description of the characteristic of the deposits in the upper Devonian complex TPОGP.
Oil deposits in this complex dedicated to a wide stratigraphic range (from domanic to numilog horizon). They are associated with the carbonate formations of different nature – reef arrays, “silt” hills, shelf buildings, formation carbonates in “backreef” zone, depression Dominicaine sediments at the foot of the reef massifs, with paleomagnetism in the area of uncompensated depression.
Petroleum potential of the considered complex is provided by a combination of reservoir rocks, local and zonal tires, traps, as well as the presence in the complex, and the underlying Paleozoic sediments of petroleum generating ones strata.
Zone reefs are complex areas of oil and gas accumulation. These long linear areas favorable for the accumulation of hydrocarbons in the process of lateral and vertical migration. Source lateral migration are domanic and Dominicaine deposits, vertical – underlying sediments of the Paleozoic.
The outer contour of the distribution of hydrocarbon deposits in the study area coincides with the reef area domanic age. This reef area of the upper Devonian middle and low-capacious carbonate reservoirs in “backreef” zone during testing were obtained only tributaries water. This is probably due to several causes: 1) the relative remoteness of the petroleum generating ones (domanic and domeniconi) strata in the upper Devonian complex; 2) the presence of barriers to lateral migration of hydrocarbons in the form of reef areas, which are already in sedimentary basins represented a tectonic-sedimentary traps and could catch hydrocarbons; 3) lack of generating hydrocarbons clay-sand-silt-middle Devonian sediments and distribution of red-colored facies in the sections of the Silurian and lower Devonian.
Major deposits of oil in the upper Devonian complex TPОGP concentrated under local and zonal tires, which rarely overlap reef strata, and they are most often located above overreef sediments.
Protection of pipelines from internal and external corrosion – one of the biggest challenges pursued by the organizations operating these networks. With proper and reliable protection against corrosion of underground and aboveground piping reduced the cost of their repair or complete replacement, which gives a huge economic impact. Existing methods for condition monitoring of corrosion protection have serious drawbacks, chief of which is that due to the large time interval between visits protection stations staff holds the delay in the detection of irregularities in their work, which contributes to the danger of failures and accidents. The article provides a solution to this problem, namely, we present a method of automated control state gas pipeline corrosion protection. For this purpose, a local subsystem multifunctional information-measuring system (IMS) gas transportation enterprises (GTE), which consists of three parts, exchanging information with each other and allows for Drugs radio control operation of the system directly from the control center. For reliable and trouble-free operation, information-measuring system must perform a sequence of specific actions. It is for this algorithm is developed automated condition monitoring of corrosion protection gas pipeline, through which we can interrogate items controlled cathodic protection station, manage, to determine their performance. The block diagram and description of the algorithm presented in the paper.