Ongoing water-resource depletion is a common trend in southeastern Kazakhstan and in most of Central Asia, making the use of drainage water for freshwater preservation and groundwater recharge a key strategy for sustainable agriculture. Since the Ily River inflow began to decrease, groundwater levels in the Shengeldy study area site have fallen below the drainage pipes. As such, our main research hypothesis was that owing to drainage infiltration, the regional shallow aquifer can be used as an effective additional water source for moistening crop root systems during the irrigation period. The MODFLOW groundwater flow model was used to simulate and quantitatively assess the combined hydrogeological and irrigation conditions of artificial groundwater recharge both from the subsurface drainage and as an additional source for irrigation. The field study showed that the additional groundwater table elevation will reach approximately 1.5 m under the field drainage system and that the additional groundwater recharge influence zone will develop up to 300–350 m from the drains. The MODFLOW simulation together with full-scale experimental studies suggests that under certain conditions drainage water can be applied both as an additional source of irrigation and for aquifer sustainable maintenance.

Purpose. Research and optimization of the processes of operation of wells equipped with plunger rod pumps in conditions with increased complexity, such as high oil viscosity, high pressure, aggressive geological and physical conditions and significant fluctuations in flow rate, in order to increase the efficiency and reliability of the plunger rod pump (UPSH) installation, increase well productivity and reduce operating costs. Methodology. The authors used the following scientific methods: the method of analysis and synthesis – for a review and systematization of existing scientific publications and experiments on the operation of wells with UPR in conditions of increased complexity; the method of observation and data analysis – for an analysis of the operation of UPR in various conditions, including the study of the effectiveness of their work in difficult geological conditions; experimental methods – for conducting field experiments to evaluate the work of UPSH in conditions of increased complexity. Findings. The use of inhibitors, tubing (tubing and compressor tubes) with protective coating, rod centralizers and special pumps is proposed to combat wiping and deposits in deep pumping equipment. Low-cost options are recommended for use in small and medium-sized wells up to 1,500 m deep, providing an efficiency of 50‒60 % with a viscosity of up to 200 MPaˑs and a sand content of up to 10 %. Originality. The theory of the causes of the failure of the GNR and the downtime of the mechanized fund of production wells equipped with UPSH has been further developed. The influence of complicated conditions on the operational characteristics of plunger rod pumps has been established. The use of OPN in production wells at the Uzen field is justified, taking into account technical and economic factors in comparison with other methods of operation. Practical value. The development and implementation of methods that increase the inter-repair period of wells at the Uzen field make it possible to reduce the cost of repair and preventive maintenance, increase the efficiency of operation and reliability of the mining complex, especially at a late stage of field development. As a result of the pilot tests conducted, the average duration of the inter-repair period of the mechanized fund in 2021 increased by 14 days compared to 2018.

The peculiarities of the collimation zones of the productive formation are taken into account when rotary drilling of wells using drilling mud. A brief analysis of the most common and fundamentally different decollatation procedures, such as washing wells with water, pumping and gelation, is presented. A very effective and promising method of decollatation using the implosion effect has a special influence. A detailed example of a well-known device is given with an analysis of the features of its application, as well as significant disadvantages in the form of complexity and functionality, high cost. A fundamentally different new device was developed and proposed, free from all the disadvantages of the opposite device for which the invention was requested. This eliminates the use of pumping and compressor pipes and their sealing, as well as a sealant for the neck. There is also no need for a compressor and surface wiring with numerous valves. Replacing the intake valve valve with a disc valve eliminates the possibility of closing the intake valve as a result of the influx of reservoir fluid with a high content of collating materials caused by the implosion effect. The design and functioning features of the proposed device and its individual elements are taken into account both when creating a single, and with any number of repeated implosive effects. The generation limits necessary for the explosion effect of the liquid-filled space were mathematically analyzed to prevent the case from crumpling under the hydrostatic pressure of the solution remaining in the storage space. An example of the dependence of the permissible length of empty space on the thickness of the housing column and, in particular, on the thickness of the walls is illustrated using a computer program.