One of the most common complications during the operation of wells in oil fields is the formation of sand. During the formation of sand wells, time stops, their repair takes a long time, as a result, there is a significant loss of production of the well. A floating sand with liquid entering the bottom of a well, destroys the working equipment, loses speed and breaks down at the bottom of the well, forming a sand plug. Removal of sand plugs requires a lot of labor, but sometimes leads to the loss of oil in many wells and the destruction of rocks in the subsurface zone of wells and deformation of the operating pipeline. One of the most pressing problems in the oil industry today is to prevent rock particles from collapsing in the wellbore area and sand accumulation. Despite numerous scientific studies and mining experiments on the sand prevention mechanism, no universal method of sand control has been found. Studies show that the load on the walls of the protective pipeline is the main cause of failure of wells as a result of deformation of the pipeline within the operating facility. Sand block formation during the operation of fragile, poorly cemented reservoirs is an important factor in the close relationship between production line deformation and sand block formation in the well, which requires consideration of the geological and operational characteristics of the field an object. The internal structure of the formation usually changes before the collector rocks are washed away by the infiltration stream. Changes in rock structure during the filtration process occur as a result of mechanical suffocation and compaction of rocks (separation of particles in the rock under the influence of pressure gradients during the movement of oils containing heavy particles in the formation). The most effective way to combat wellhead flushing and sand blockage is to reduce the amount of fluid removed from the formation. This is due to the regulation of the pressure drop in the wellbore. Rock collapse is accompanied by the introduction of sand grains into the wellbore, thereby continuously reducing the permeability of the wellbore zone. However, the sharp decline in well yields is not due to a decrease in the permeability of the formation, but to the high resistance created by the blockage, which closes the filter section and is formed by small sand grains. Colmatization of mechanical mixtures in the wellbore area, contamination of the wellbore, increased vibrations and more intensive wear of the equipment inside the well create serious complications. Despite the widespread use of rod depth pumps, their operation in sand wells is complicated. As a result, the voltage on the rods and the electric motor increases, the rods are stretched, broken, the pliers are idle, the electric motor is overloaded, and so on. occurs. The formation of sand plugs is more pronounced in the final stages of field development. At the moment, due to the sand plugs in the wells, they often stop for repairs, which reduces of the time between repairs and increases the over-all operating costs. Therefore, one of the most pressing issues facing oil workers is to study the causes of sand plugs, to investigate the processes taking place in the plug zone and to develop effective methods to combat sand by analyzing the operation of such wells. If the sand completely closes the filter of the production casing and as a result the flow of liquid to the bottom hole is completely stopped, such a complication can be eliminated by either washing the bottom hole or strengthening the well hole zone. However, in many cases this technology does not work or is not cost-effective. Based on the results of the study, indicator diagrams or graphs of changes in the percentage of oil, water, gas and sand are plotted depending on the pressure in the well or the dynamic level, as well as adjustment curves, i.e. graphs of the dependence of these indicators on the parameters of deep pumping. According to the results of studies carried out by measuring the dynamic level of a deep pump, an indicator diagram can be constructed using the method. This method consists of recording dynamic levels on the same scale selected on the vertical axis, plotting the level drops on the right axis, and recording the percentages of liquid, oil, water, gas, and sand on the horizontal axis. The amount of sand recovered can be expressed in volumes or units of weight. Liquid, oil and water debits should be taken on the same scale. They select the appropriate scale for gas and GOR as well as the percentage of sand, and the level drawdown (difference between static and dynamic levels) is also determined as fluid levels are measured from the wellhead. In order to investigate the impact of mechanical mixtures on the operation of the pump and to determine the measures to be taken, information was collected on the repairs carried out in the shaft depth pump wells on the of “Azneft” PU. Keywords: sand, pump, plunger, cylinder, pump-compressor pipes, mechanical particles, coagulation.
The final stage of development and operation of oil fields is accompanied by many problems, one of which is the most characteristic, the complications due to the intensive flow of sand from the reservoir to the bottom hole. As the liquid seeps through the rocks from poor collector properties, its skeleton collapses in the bottom hole zone and sand grains begin to flow into the bottom hole. Sand particles accumulate in the bottom hole zone and formation of sand plugs which reduces the productivity of the well and in most cases completely stops its operation. The formation of sand plugs is more pronounced in the final stages of field development. At the moment, due to the sand plugs in the wells, they often stop for repairs, which reduces of the time between repairs and increases the over-all operating costs. Therefore, one of the most pressing issues facing oil workers is to study the causes of sand plugs, to investigate the processes taking place in the plug zone and to develop effective methods to combat sand by analyzing the operation of such wells. If the sand completely closes the filter of the production casing and as a result the flow of liquid to the bottom hole is completely stopped, such a complication can be eliminated by either washing the bottom hole or strengthening the well hole zone. However, in many cases this technology does not work or is not cost-effective. At present, the measures taken against oil accumulation in oil wells, sand in the well hole zone (using small sized lifting pipes, mounting of special tails, injection of liquid into the annulus, mounting of sand anchors at the entry of deep well pump, strengthening of the well hole zone, etc.) are somewhat justified and still does not give the desired result. Due to the problems caused by the sand plug, the repair time of the wells is reduced and the operating costs continue to increase. Colmatization of mechanical mixtures in the wellbore area, contamination of the wellbore, increased vibrations and more intensive wear of the equipment inside the well create serious complications. Despite the widespread use of rod depth pumps, their operation in sand wells is complicated. As a result, the voltage on the rods and the electric motor increases, the rods are stretched, broken, the pliers are idle, the electric motor is overloaded, and so on. occurs. If the reservoir consists of grains of sand and brittle sandstones, then in such wells there is an intensive occurrence of sand. Grains of sand increase the number of routine and workover operations in the well, gradually reducing oil production. This creates various deformations and difficulties in the production line. The pipeline has been undergoing major repairs for a long time. To avoid this, the technology of measures is carried out in the following sequence: The aggregate is mixed with cement powder and water to prepare the grouting slurry; A special volume of cement slurry, calculated using the pumping unit, is pumped into the hole and stored there until complete solidification; The solution applied to the layer hardens and cements the grains of sand together. As a result of the measure, the grains of sand at the bottom of the well are strengthened with each other, and the number of sand manifestations in the well is reduced. If a sand plug forms in the filtering part of the well, the lower part of the installation experiences more back pressure than the upper part. For this reason, the outflow of fluid from the lower parts of the reservoir occurs at a pressure lower than the pressure in the well. A sharp decrease in the flow rate of the well occurs due to the accumulation of sand grains in the well and the formation of sand plugs in the pipes of the elevator. The length of pipes covered with sand plugs increases many times. Thus, due to the fact that the permeability of the sand plug is several times higher than the permeability of the reservoir, due to the large difference in the cross-sectional area of the perforated part of the well and the pipe, hydraulic losses during the movement of liquid (oil) through the sand plug are comparable to possible. During the entire life of the wells, the wellbore area is subject to shocks and periodic loads, which affects the quality of the sand barrier created in this area. In this regard, the issue of developing special buffering systems for wells subject to significant dynamic loads, which can ensure the integrity of the cement barrier in the wellbore area, is relevant. Experimental studies have been conducted in the laboratory to create a more efficient fastening technology in the wellbore area. As a result of laboratory studies, cement, natural zeolite and chloride as a material that prevents the collapse of the cement barrier in the wellbore area and limits the appearance of sand an aqueous solution of acid ( ) was proposed. Keywords: sand, pump, mechanical particles, coagulation, nanoparticles, hydrochloric acid, deformation resistance, dynamic loads
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