FOAM GENERATOR EQUIPMENT
BACKGROUND OF THE INVENTION In the drilling of oil wells, in addition to equipment, and specialized techniques, also special fluids, called drilling fluids are used. Drilling fluids are classified based on their main component, which represents the highest volume per cubic meter, as water-base and oil-base fluids. They are additionally composed of viscosifying materials such as clay and polymers, as well as using densifying materials such as barite and calcium carbonate. Even more specialized materials are used as inhibitors of clay hydration, natural and synthetic polymers, lubricants, emulsifiers, and very recently foam materials have also been used. In drilling equipment, drilling fluids are prepared in reservoirs called mud dams, (figural), with an average capacity of 45 to 60 M3, which are equipped with funnels and agitators. The funnels (A) are used to facilitate the addition of the materials to the base liquid of the system (water, oil or emulsion of both), the agitators (B) allow the mixing of the materials with the base liquid. The drilling fluids are indispensable to carry out the drilling of the well because they allow to establish circulation in it, in a closed circuit, as described in the diagram "hydraulic system of circulation" In this system the circulation circuit consists of In filling the reservoirs called mud dams (1), with the drilling fluid to be used, the fluid is sucked by the mud pumps (2), which send it to the vertical pipe (3), which through the hose perforation (4) arrives at the rotating union (5), passing through the arrow (6), to the perforation pipe (7), through which it is conducted to the auger (8), from which it comes out through the holes called nozzles (9), hitting the bottom of the newly opened hole (10), captures the cuttings, and starts its ascent to the surface through the annular space (11) between the hole dug by the auger and the drilling pipes, reaching the surface It is filtered in the vibratory screens (12), where it is cleaned of the rock cuttings, again reaching the mud dams, closing the circuit. The drilling fluids are designed to develop and fulfill important functions inside and outside the well. The main functions of the drilling fluids are: • They have traditionally been used to keep the formation pressure under control, which is the pressure to which the fluids inside the pores of the rock are subjected, preventing them from flowing to the surface. • Cool and lubricate the bit (figure 2), a tool with which the rock is drilled, going deep into the earth's crust to where the oil field is located, by means of the continuous circulation of the fluid from the surface to the bottom and through the auger, from the bottom to the surface an exchange of heat is achieved, which is adsorbed at the bottom of the well and dissipated on the surface. • Cleaning of the hole, through the circulation of the fluid, and due to its degree of viscosity, it is able to collect and maintain within its colloidal structure the pieces of rock (gravel), which the action of the auger generates, taking them to the surface. This action allows the auger and other tools used during drilling to remain clean on the outside and can perform the work of efficiently grinding the rock, because if these formation cuttings are not removed from the bottom of the well, the auger can be choking when coined by the solids that are deposited on it, which would suspend the drilling operations. For drilling fluids to effectively perform the functions described, which are part of an even larger list, it is necessary that the drilling fluid be maintained in continuous circulation, as described above, since if for some reason the circulation circuit of the drilling fluid is interrupted, the perforation of the well will be consequently suspended. The main causes of the interruption of the flow of the fluid are: • Mechanical failure of the mud pump, because it is the generator of the flow in the hydraulic system • Failure in any of the components of the drill string, which usually it is due to the leakage of the fluid in some connection, which is deteriorated by the action of the fluid flow under pressure. • Loss of circulation, which is the flow of the drilling fluid towards the formation, which may be partial, when part of the fluid injected into the well manages to return to the surface, or total, when all the injected fluid is lost among the perforated rock, no return to the surface. This is mainly due to the fact that when the hydrostatic column generated by the drilling fluid is greater than the pressure of the formation, it overcomes it by penetrating between the pores of the rock due to its permeability. It also occurs because with the movement of the earth's crust, the rock layers fracture, generating large, wide and long cracks, or multiple micro fractures with which the rock behaves like superimposed domino tokens, but without consistency, being These two situations are the most difficult conditions to solve, because fluids flow with great ease through these channels. To solve the condition of total loss of circulation, and trying to avoid the flow of fluids towards the formation, blocking this type of fractures or faults, obturantes materials have been used, such as crushed walnut shell, cellophane paper, gelatins, special fluids and highly expensive, etc., without achieving the objective of blocking these fractures or faults, allowing the circulation and drilling of wells in areas of low pressure and fractured, causing large economic losses, which can be of the order of half the total cost of the perforation of the whole well, even the total loss of circulation is the cause of the loss of the well.
The solution to this costly problem of loss of circulation, with great benefits for the oil industry, has been the use of foaming 95 fluids. The system of foamed drilling fluid is a system based on fresh water, sea water or diesel oil, to which clay, polymers and a foaming agent are added, this fluid is mixed with a gas, which is retained in the system in the form of bubbles. 100 However, despite the density of the foamed fluid, which is generated "in situ", by contact of the fluid with the gas in its journey through the perforation pipes, the bubbles are of different sizes. Due to the difference of diameters in the bubbles, occluded in the system, this becomes unstable, with movement independent of the bubbles, and having greater
105 pressure that others, the more pressure higher penetrate the lower pressure, coalescing, and forming larger bubbles by sharing the volume of both gas in a single, larger and lower pressure, repeating the phenomenon infinitely; with this, the density of the system is caused to be different in each segment of the well drilled. 110 Having large bubbles, the hydrostatic pressure above them, compresses them greatly, becoming the density resulting from the fluid almost the same as that of the base liquid. To solve this adverse phenomenon for the purpose of obtaining circulation by drilling wells in low pressure areas or fracturing with foamed fluids, this foam generator has been designed and successfully tested, which has demonstrated its high efficiency in the mixing of liquids and gases , in the application of foamed fluids, of recent creation and incorporation into the technology of oil well drilling fluids. The use of the foam generator allows to obtain homogenous micro bubbles and 120 with a size smaller than 30 microns, allowing to maintain the density of the foamed fluid practically the same in the whole well, with which the stability and performance of the foamed fluids is greatly increased and meets all the requirements established for this type of systems.
Having demonstrated its great capacity, performance and efficiency to generate 125 foam, this foam generator is intended to protect by means of the present application for patent registration, because it is a totally different and unique in its kind, high performance, Easy and safe to operate, with high level of pressure resistance.
DESCRIPTION OF THE INVENTION
The foam generator and material mixer, figure 3, is a team consisting of a cylinder, with connections at the ends to allow the entrance (C) and the outlet (D) of the fluids, with capacity to handle internal pressures up to 8000 psi. The entrance of fluids in turn has two entrances, forming what is known as Greek i? Of circulation, one is to allow the entrance of liquids (E) and the other for gases (F) .These liquids and gases are pumped to the foam generator by the pumps for lodes and air compressors or nitrogen pumps, as shown in the diagram "subnormal hydraulic circulation system" The foam generator has a series of plates inside, Figure 4, with multiple orifices (G) of different sizes, in the form of nozzles, Figure 5, through which the fluids flow in turbulent flow, allowing the mixing of these.The nozzle plates are separated and attached at the same time by plates (H), which measure 10 times the thickness of the plate, 4 times as wide and as thick as the nozzle plates.The foam generating equipment, for the purpose of generating the foamed fluid, is installed , in a drilling rig, com or is shown in the diagram "hydraulic circulation system", The mixing process is repeated as many times as plates, (figure 6), have inside the foam generator, installing even more than one foam generator if necessary, in such a way that more and more parts of the fluids flowing through the nozzles are fractioned, obtaining a greater degree of mixing and greater stability in the foam. This is for the purpose of allowing the generation of sudden and sudden changes in speed and type of flow, alternating laminar and turbulent, where the parts of fluid flowing through a nozzle can be exchanged with the fluid parts flowing through a different one. .
Immediately a new part of the fluids enters the foam generator, they move those inside the generator, passing them through the next plate, with a turbulent flow again, drastically increasing the level of mixing, since the parts of the Fluids and materials are getting smaller and smaller. In addition to the flow of fluid from a nozzle in the form of jet, under pressure, and when hitting the next place, the linear flow becomes radial flow, allowing the parts of fluids are exchanged and combined faster and more efficient way What makes this equipment innovative and special is its design, which gives it the ability to homogeneously mix liquids, solids and gases, by means of a simple mechanism, without motors, or moving parts . Having as main characteristic, the power to increase the number of nozzles, combining the plates of nozzles with different diameters of nozzles, adapting it for the mixing of different particle sizes and liquid and gas ratios. In addition to the great ease of handling, because its tubular shape, does not require special assemblies. Its connection to the circulation system in a drilling rig is simple, since it is based on fast joints. In addition, this foam generator is not limited to the oil industry, it can be used in any activity that requires mixing liquids with solids and gases.