FEATURES OF TECHNICAL AND TECHNOLOGICAL SUPPORT FOR WELL CASING AND CEMENTING OPERATIONS
Abstract
Purpose. A detailed analytical and laboratory study of the basic factors for the reliable implementation of processes for fastening and cementing production oil and gas wells. The mentioned wells are characterized by the presence of complex geological, lithological and technological conditions for them. The abovementioned is previously achieved through the development and implementation of innovative techniques and methods of wellbore quality assurance.
Methods. The study of the main features of well construction in difficult conditions, in particular the processes of their preparation for casing and subsequent cementing, was carried out using modern methods of analytical analysis and experimental research. This was done using mathematical and physical modeling techniques, modeling techniques and processing research results in the SolidWorks, STATGRAPHICS, MATHCAD environment, instrumentation and relevant materials. The study of circulation processes during operation of the designed device was carried out on a special stand. The specified stand can be used when conducting experimental tests of the performance of devices for treating a wellbore under conditions as close as possible to real ones. This feature of the stand makes it possible to obtain completely reliable local quantitative hydro-aerodynamic characteristics of the flows of circulating agents caused by the work of the executive bodies of the models under study. Also, the stand in question can be used to study sludge accumulation processes, with a wide variation in the technological parameters of the cleaning cycle, in complicated cavernous sections of a well under construction.
Findings. The main problematic issues in the development of oil and gas fields are analyzed, taking into account the need to create reliable channels for transporting hydrocarbon raw materials. Key requirements are formulated for the technological cycle of operations for fastening and subsequent cementing of a wellbore, complicated by the presence of thick layers of sedimentary deposits with cavernous workings in them. Some significant directions for improving technical and technological techniques and methods for the well casing cycle in difficult geological and lithological conditions are outlined. Techniques and methods for preparing the wellbore for running the casing with its subsequent fastening were selected as a priority direction for the development of well casing technology. The necessity of establishing the physical and hydraulic essence of the phenomena and processes that occur during the operation of devices for processing the trunk of a well under construction is substantiated. The prospects of using devices for treating the wellbore are shown, which allow creating active movement of the flushing fluid in the stagnant zones of the specified mine workings.
Originality. It is cavernousness that is the main reason for the sharp decrease in the quality of cement stone in the annulus of the wellbore. This circumstance is due to the active mixing of cement mortar with clay-sludge deposits, which are located in caverns and must be removed during appropriate shaft preparation.
Practical implications. A fundamentally different design of the designed device and the mechanism of its action on cavernous clay-sludge formations makes it possible to significantly accelerate and direct the flow of washing liquid to treatment objects, in particular clay-sludge pastes. This allows you to significantly increase the quality of cleaning cavernous intervals, and therefore, as a consequence, plugging the wellbore. This is a direct basis for a significant reduction in material costs and time to eliminate complications and accidents associated with poor-quality packing; due to the above, the maintenance-free life of the well’s operation and maintenance will increase, and the rates of mineral extraction will increase.
