Fundamentals of oil and gas industry A well is a cylindrical mine, constructed without human access to it and having a diameter many times smaller than its length. Well drilling is the process ofconstructing a well by destroying rocks. Drilling Well Elements: • the upper part of the well is the mouth (1); • bottom - face (2); • side surface - wall (3); • the space bounded by the wall is theborehole (5) • casing columns (6) • rock formation (7). The length of the well is the distance from the mouth to the bottom along the axis of the trunk (4). The depth of the well is the projection of thelength on the vertical axis. Core Wells are deepened, destroying the rock over the entire face area (solid face, a) or along its peripheral part (ring face, b). When drilling with an annular face, a core rock column remains in the center of the well, which is periodically raised to the surface fordirect study. Diagram of a well drilled with a solid (a) and an annular face (b) Classification of wells by purpose • Exploration – to identify productive formations, study the size and structure of the deposit, and the like. • Operational – for oil, gas and gas condensate production. • Injection - for pumping water (less often air, gas) into productive horizons in order to maintain reservoir pressure. • Observational - to control the development of deposits. • Prospecting – for the discovery of new industrial deposits of oil and gas. • Reference wells are laid in areas unexplored by drilling, serve to study the composition and age of the composing rocks. • Parametric – to study the geological structure of a little-known area and the prospects of its oil and gas potential. • Structural – to identify promising areas and prepare them for exploratory drilling. Well construction cycle 1. 2. 3. 4. 5. preparatory work; installation of the tower and equipment; preparation for drilling; drilling process; opening of the reservoir and testing for the inflow of oil and gas. Drilling methods Mechanical: • rotational methods (роторное, турбинное, реактивно-турбинное бурение и бурение с использованием электробура и винтовых забойных двигателей); • shock methods. Non - mechanical: • • • • • thermal; electric; explosive; hydraulic; etc. Drilling depth small up to 1500 m to medium depths up to 4500 m deep ultra - deep up to 6000 m deeper than 6000 m For your information … • The initial diameter of oil and gas wells usually does not exceed 900 mm, and the final diameter is rarely less than 165 mm. • The depths of oil and gas wells vary within a fewthousand meters. • The deepest well in the world was drilled on the Kola Peninsula in 1994 (Kola ultra-deep well). Its depth is over 12 kilometers. • In 2007, Sakhalin oilmen broke the world record for drilling the longest inclined oil well: in 61 days they drilled a well with a diameter of 215 mm, which went under the bottom of the Sea of Okhotsk by 11,282 m. Well construction Fountain fittings ПВО Column head Conductor Operational column Caverns The borehole Zone productive formation Slaughter Perforation zone The drilling process includes a number of operations: • The descent of drill pipes with a destructive tool into the well. • Destruction of the rock face. • Extraction of the destroyed rock from thewell. • Lifting drill pipes from thewell to change the working destructive tool. • Strengthening the walls of the well when determining a certain depth with casing pipes, followed by cementing the spacebetween the wall of the well and the deflated pipes (separation of layers). Drilling rig • drilling equipment (hoisting mechanism, pumps, drilling winch, swivel, rotor, power drive, etc.); • drilling structures (derrick, foundations, etc.); • equipment for mechanization of labor-intensive work (mechanisms for automation of descent and lifting operations, automatic drilling wrench, remote control of drilling processes, control posts); • equipment for preparation, cleaning and regeneration of drilling mud (preparation unit, vibrating screen, sand and silt separators, containers for chemicals, water and drilling mud); • manifold (discharge line in block design, throttle-shut-off devices); • devices for heating drilling rig blocks. Drilling in winter Drilling rig On the drilling rig: lead pipe, control panel Bush wells Cluster drilling is the construction of groups of wells from a common base of a limited area on which the drilling rig and equipment are located. It is produced convenient sites for reduce the time and distance between the than 3 m. in the absence of drilling rigs and to cost of drilling. The wellheads is not less Power transmission lines, bush wells Drilling rigs Single - support tower Two - support(A-shaped) tower Tower type tower Drilling rigs in offshore territories A self-lifting drilling platform is a floating pontoon with a cutout, above which there is a drilling rig with drilling and auxiliary equipment, a multi-storey cabin with cabins for crew and workers, a power plant and warehouses. Multi-meter columns-supports are installed at the corners of the platform. Semi-submersible drilling platforms are used at depths of 300 - 600 m. They do not rest on the seabed, but float above the drilling site on huge pontoons. Gravity-type drilling platforms are equipped with a powerful concrete base resting on the seabed. Thank you for your attention!
