Perm Journal of Petroleum and Mining Engineering

In the article an account of extensive investigations of a well with carbonate deposits operating over a period of 44 months in Perm Region is given. Two well production enhancement techniques were used, namely abrasive jet perforation and acid treatment. A detailed analysis of abrasive jet perforation and acid treatment results was carried out, where changes of productivity index depending on reservoir and bottomhole pressures after operations were evaluated. It was shown, that an incremental oil production can significantly decrease with decreasing reservoir and bottomhole pressures. It was found that during the abrasive jet perforation with acid treatment, an incremental oil production has increased for abrasive jet perforation and acid treatment to about 65 % and 35 % respectively. It was also shown, that the abrasive jet perforation helps to slightly increase a well rate and decrease a reservoir energy consumption for fluid communications in bottomhole formation zone. After the acid treatment taking place two years later, oil production was increased and it is understood that 15 % of this increase is due to acid attack, and on 85 % due to growth in bottomhole pressure and fracture permeability. There was revealed a complete exclusion of reservoir energy consumptions to overcome the additional filtration resistance immediately after conducting operations. The reservoir has an excellent intrinsic fracturing property, so bottomhole formation permeability and energy consumption significantly depend on the reservoir and bottomhole pressures. It is recommended to maintain reservoir and bottomhole pressures higher than lateral rock pressure to increase effectiveness of well operations in reservoirs with advanced natural fracturing.

One of the important tasks of effective well operation in oil fields is to prevent clogging of bottomhole formation zone in the process of various geological and technical measures. As one of the most promising means to prevent reservoir productivity decreasing a technology using downhole shutoff valves has been proposed. Summary of the technology consists in application of a deep reservoir protection system, which is hermetically mounted in the well and dividing the productive formation area and pumping equipment placement. The analysis showed that the known shutoff valves configurations (systems with hydraulic, mechanical, electric drive) does not allow to carry out research on monitoring the development of operated object. Accordingly, none of the configurations has not been accepted for industrial use so far. The paper proposes a new mechanical reservoir protection system (including the bottomhole shutoff valve), providing a hermetic separation of productive reservoir and area of killing fluid injection when the differential pressure is up to 10 MPa. The basis of the shutoff valve construction is the principle of ball valve, in closed position the ball is pressed to valve seat by pressure, which creates a resistance to its opening. In order to achieve a high equipment`s operating time in design a special attention was paid to ensure device operation with the presence of well complications. To solve this problem a special sludge trap was included in the equipment and it was placed between the hollow plunger and the pump unit with a back pressure valve and a perforated pipe inside. Calculations of sludge trap filling were made according to the different number of stops and at various concentrations of mechanical impurities. As a result of calculations conclusions about the strength conditions fulfillment for geometric dimensions specified for pairs of steel-polyamide and steel-Zedex materials were made. Proposed device construction ensures a reliable isolation between under and above packer space, preventing ingress of killing fluid in the bottomhole formation zone. Universal equipment configuration extends its application area and the possibility of its use in combination with any pump unit depending on well conditions.

Article proposes a statistical approach in predicting the gas-dynamic danger in potash mines, which can significantly reduce the dependence of the final prediction results on subjective factors by introducing a model of informative strictly defined criteria. Obtaining the most appropriate forecasting models of reality is only possible through an integrated approach, displaying factors of generation, migration, accumulation and preservation for a long period of geological time gas clusters and centers of gas-dynamic phenomena in the salt rock mass. In the mathematical model development for of gas-dynamic phenomena`s prediction method on geological data a parametric mathematical model of forecasting method was used based on discriminant analysis, which is a powerful statistical method and in depth of data analysis and the results significance is among the most effective methods of statistical analysis. In case of compliance with conditions of multidimensional data normal distribution and equality of covariance matrices the parametric model leads to optimal results in forecasting. In case of non-compliance with these restrictions in the use of robust evaluation model allows to compensate the incorrect prediction`s probability growth. A statistical analysis of geological information in the field of gas-dynamic phenomena (GDP) in the potash mines was performed. Learning samples were formed, the mathematical model of forecasting method for zones dangerous because of GDP was developed based on multivariate discriminant analysis with classical and robust statistical procedures. Decision rules to predict the geological data of areas dangerous because of GDP were obtained for conditions of Verkhnekamskoie potash salt deposit. Forecast maps were created for zones dangerous because of GDP for the Ust-Yaivinskii mine field conditions on the base of PJSC "Uralkali" and Polovodovskii area of Verkhnekamskoie potash salt deposit. The adequacy estimation was given for the method of forecasting mining operations` practice on potash layers dangerous because of GDP in conditions of potash mine fields PJSC "Uralkali".

The growth in marble quarrying requires the implementation at mining enterprises new high-performance equipment. In this connection, it is advisable to consider the possibility of use in the development of marble deposits surface milling miners. To improve the efficiency of their operation it is necessary develop a technique of operational definition of surface miners` basic parameters according to conditions existing at marble mining enterprises. Experience shows that when choosing miner`s model the determination of its parameters can be carried out using regression dependences. As a result of processing initial information about technical characteristics of surface miners the dependences determining connection between milling width, engine power and operating weight were obtained. In the largest Russian Koelginskoe marble deposit during 2014-2015 chronometer monitoring the work of surface milling miner Wirtgen 2500SM were conducted in different modes and conditions. In the study miner`s speed was varied from 7 to 9 m/min and cutting depth from 0.1 to 0.15 m. Surface miner worked according to the shuttle scheme with a turn at the end of the site. Rock was loaded into dump trucks with carrying capacity of 25-30 tons. Processing of observational results allowed to get dependence for the operational definition of miner`s performance in marble deposits developing. A nomogram for determining the engine power, weight and miner`s operational performance with different milling widths was constructed. Dependences obtained during the study can be used when selecting miner for a particular deposit, as well as when forecasting engine power, operating weight and performance of surface miner`s perspective models.

The use of materials based on natural potassium salts is a known way to create a high-quality, up to healing, indoor air which is modified due to the effect of sylvinite, carnallite and halite aerosol particles. Facing or decorating protective surfaces of walls, floor or ceiling in special ground facilities - speleoclimatic chambers - can enrich the indoor air with a highly dispersed salt aerosol and aeroions of light mobility group. It is proposed to look over the interrelation between distribution of aerosol particles and concentration of light aeroions in sylvinite speleoclimatic chambers, considering the ionization and recombination equation of formation and disappearance of light aeroions. By extrapolation the main parameters of the highly dispersed salt aerosol were determined for size less than 0.3 microns based on the experimentally determined parameters of aerosol particles distribution by size (greater than 0.3 microns) taking into account possible solutions of the aeroionic balance equation and applying the superposition model of several logarithmically normal distributions. On example of Verkhnekamskoie potash deposit the article shows the main parameters of aerosol particles` size distribution in sylvinite speleoclimatic chambers with surfaces of different constructions made of sawn natural sylvinite blocks, panels and molded salt tiles with a high content of potassium chloride, a component of potash salts. Study results confirm high efficiency of sylvinite building materials application to create a high-quality medical or wellness air environment saturated with highly dispersed salt aerosol, and allow to optimally select special constructive and decorative materials on the basis of sylvinite, depending on required parameters of the aerosol distribution in order to create a high-quality indoor air.