Transactions on Engineering and Computer Science

Abstract 

At present, oil production is characterized by the increased development of new deposits with poor reservoir properties. All of this is leading to the application of ESP units with low capacity and high head in oil production. At some oil-production enterprises, the number of wells equipped with low-capacity ESP units can account for more than half of the existing stock. Moreover, low-capacity ESP units provide for the bulk of oil production. The operation of such ESP units in oil production results in complications associated with the unit’s parameters or the properties of high-pressure product water. To date, over twenty techniques have been developed for estimating the condition of product water, and measures have been taken to control the related complications. One of these measures involves reinforcement of the ESP unit’s cable line and downhole motor. Increasing the thermal strength of the cable line being used as part of the ESP unit reduces the number of electrical failures (R-0) of the equipment. However, the operation of a centrifugal pump at high temperatures leads to salt deposition inside the pump’s internal components. The theory and practice of salt deposition control, as developed by the author of this paper, is described in many works and monographs. It was a theoretically demonstrated that the operation of a low-capacity ESP unit is always accompanied by a temperature rise of the downhole motor and centrifugal pump. A downhole motor with a greater diameter than the centrifugal pump always participates in contact heat exchange with the production string; hence, its temperature is only slightly dependent on the properties of the pumped gas-liquid mixture. The centrifugal pump is the focus of the study of the ESP unit’s thermal behavior. During the pumping of complex mixtures, the centrifugal pump is always impacted by high temperatures. The main point discussed in the aforementioned works deals with identifying the thermal behavior of a centrifugal pump as a function of formation-fluid properties and the parameters of the pump itself. The study of the pump’s temperature as a function of the properties of the pumped gasliquid mixture allows us to solve two major problems: 1) complications during the low-capacity ESP unit’s operation; 2) automation of the centrifugal pump’s control. ESP unit automation will open up the possibility of developing clean oilproduction technology and a transition to “digital oil fields.”

 Keywords: Oil well operation with ESP units, Decline in well output, Growth of low-capacity wells, Centrifugal pump, Prediction of salt deposition, Control automation