Perm Journal of Petroleum and Mining Engineering

The problem of forecasting the hydrodynamic connection between the production and injection wells in the flooding area was considered according to the geological characteristics of wells according to hydrodynamic wells studies data and development indicators. To create a model for predicting hydrodynamic communication, an analysis of the results of tracer studies of the Central uplift of the Tournaisian development object in the Upper Devonian-Tournaisian carbonate deposits was carried out. The tracer studies involved 5 injection wells and 17 production wells, sampling was carried out for 6 months. These studies served as a training sample. To assess the connectivity of producing wells and wells with reservoir pressure maintenance, the dFP parameter was proposed and calculated, which characterizes the degree of influence of an injection well on producing wells in the source. According to the calculated indicator dFP , the well pairs were divided into two classes: "poor hydrodynamic connectivity" ("PC") and "good hydrodynamic connectivity" ("GC"). Analysis of the average values of the considered reservoir characteristics and development indicators in classes using Student's t-test by class showed that out of 37 indicators, 7 differences were statistically significant. When using the proposed classification in terms of dFP into classes "GC" and "PC", in 62 pairs of production and injection wells, a stepwise linear discriminant analysis (SLDA) was carried out in the training sample, which allowed obtaining the discriminant function Z for subsequent classification. The use of the obtained discriminant function and the calculated boundary value Z bound on the training sample ensured the percentage of wells correctly assigned to the "GC" group - 82.1%, for the "PC" group - 76.5%. In general, the proportion of the correct distribution in the training sample groups was 79%. An analysis of the results obtained on a test sample for the adjacent West uplift in the Tournaisian deposits showed that the use of the discriminant function Z generally provided 75% of the correct classification for all sources, which confirmed the possibility of using this model to predict hydrodynamic communication in the flood source.

The relevance of the study is related to the need to form clear ideas about the factors of successful drilling operations and make a number of generalizations to existing methods for predicting the transport and cleaning of wells with a horizontal section, taking into account the features and patterns of drilling fluid flow in real drilling modes. The features of the spatial flow of a drilling fluid with solid particles mixture in the coaxial and eccentric areas of the well were studied; regularities of the developing steady flow of the mixture along the well were established; recommendations for the practice of applied calculations of the intensification of the cleaning wells process by hydraulic methods were substantiated. A well with a 12-meter horizontal eccentric section was chosen as the object of study, in which the flow was carried out under conditions that were really close to the actual drilling parameters. The universal key to understanding the features and identifying the regularities of the processes considered in the work were the methods of mechanics of inhomogeneous continuums for viscous homogeneous and heterogeneous mixtures, computational fluid dynamics (CFD) combined with the ideas of a complex physical-mathematical and numerical study of internal flows of rheologically complex viscous media. It was established that particles could significantly affect the structure of the averaged and pulsating flow of a droplet liquid, their settling led to the formation of an inhomogeneous anisotropic flow structure, the calculation of which required modern second-order turbulence models for Reynolds stresses. It was shown that in the bottom region of the annular space there was a zone with equivalent phase velocities, where the effects of a decrease in the intensity of molar transfer with an increase in the size of the sediment layer were manifested. Real drilling conditions were characterized by processes that accompany laminarization and stabilization of the mixture flow along the entire length of the well; near the boundary of the fixed layer of settled particles, a narrow layer of their suspended state was formed. Moreover, the bringing of cuttings particles from the reservoir surface, as well as their transition to a suspended state, was mainly determined by convective-diffusion mechanisms, the intensity of the pulsating small-scale movement of vortices with an anisotropic structure and the presence of local areas with "moderately high" flow velocities in contact with a curvilinear unstable to small disturbances section surface. The conditions for the formation of a stagnant zone, in which sedimentation and growth in the size of deposits were intense, were noted. A technology and algorithm for modeling the process of interaction of two-phase flows with the walls of an eccentric pipe was recommended for practice, based on demonstrations of CFD capabilities, as well as conclusions on improving the criteria relationships for determining the minimum drilling fluid flow rates, taking into account the correction of parameters characterizing the rheological features of the mixture, turbulence intensity, annulus geometry. space and connecting nodes.

With the beginning of the civilization development, people began to extract minerals from the bowels of the Earth and transport the rock mass. The main expense in mining operations is the energy required to extract and transport ores, provided by electricity or diesel fuel, which is the main source of energy for mining companies operating in remote areas. Significant disadvantages of diesel equipment are the release of toxic substances, gas contamination of the atmosphere and increased smoke, especially at deep horizons. As a way to reduce carbon emissions and negative impact on the environment, it is important to use alternative fuels, the most environmentally friendly of which is hydrogen. Hydrogen-powered mining equipment does not pollute the air with exhaust gases, which makes the working atmosphere cleaner, especially in deep quarry or underground mining. It should also be taken into account that while the cost of diesel fuel is constantly increasing, the cost of hydrogen fuel is decreasing every year. Diesel and electricity costs in mining operations are often prohibitive given their relative isolation. The operating conditions of mining trucks and other mining equipment ensure the demand for hydrogen energy in the mining industry in terms of its decarbonization.