MXPA99011487A - Control and monitoring system for chemical treatment of an oilfield well - Google Patents

Abstract

Se describe un sistema de control y de monitoreo parasistema químico para el tratamiento químico de un pozo de un yacimiento petrolífero;de conformidad con la presente invención, el sistema de control y monitoreo de inyección química incluye la colocación de uno o más sensores en el fondo de la perforación en una zona de producción para medir las propiedades químicas del fluido producido, asíComo también para medir otros parámetros de interés en el fondo de la perforación;estos sensores están hechos preferiblemente a base de fibraóptica, y proveen un indicador de alta temperatura, confiable y relativamente económico del parámetro químico deseado;los controladores de superficie y/o fondo de perforación reciben la entrada de los diferentes sensores del fondo de la perforación, y en respuesta a los mismos, controlan la inyección de compuestos químicos en un sistema de tratamiento de agujero de pozo y/o de superficie al comunicar los sensores con ambos controladores de superficie y/o fondo de perforación, la eficacia del sistema de tratamiento de fondo de perforación o superficie es monitoreada en tiempo real y en base a la información detectada, los controladores iniciarán algún cambio, en la forma, cantidad o del compuesto químico que sea inyectado.

Description

CONTROL AND MONITORING SYSTEM FOR THE CHEMICAL TREATMENT OF A WELL OF AN OIL FIELD FIELD OF THE INVENTION The present invention relates generally to operations in oil fields, and more particularly to the monitoring and control of treatment systems for oilfield wells, including a surface treatment system that controls and monitors chemical treatments of oil and gas produced, and is directed in addition to a drilling bottom device that uses sensors and their use to monitor the condition of drilling bottom equipment, monitor certain geological conditions, monitor oil fields, monitor and control the addition of chemicals, and corrective operations.

BACKGROUND OF THE INVENTION In production wells, chemical products are often injected into the bottom of the borehole to treat production fluids. However, it can be difficult to monitor and control this injection of chemicals in real time. It is known in the art how to arrange sensors in the hole of a well to obtain information regarding the efficiency and performance of each production zone in each of the wellbores.

To carry out certain types of oil field analysis, it is necessary to know the rates of temperature rise and pressure in the wellbore. This requires measuring the temperature and pressure at selected sites at the bottom of the drilling over extended periods after closing the well on the surface. In the methods of the prior art, the well is closed on its surface, and a drilling cable tool is transported in the hole of the well and located at a point therein. The tool continuously measures the temperature and pressure, and can provide another measurement, such as flow control. These measurements are then used to carry out the oil field analysis, which may include determining the level of hydrocarbon reserves remaining in a field, the fluid flow characteristics of the production formations, the water content , etc. The prior art methods described above, do not provide continuous measurements in real time while the well is producing, and require special drilling cable tools that must be transported to the bottom of the bore. This information is used to determine the course of action, which may also include opening or closing slip sleeves to increase or decrease production speed, corrective work such as cleaning or reaming operations, closure of a particular zone. , etc. Temperature and pressure measurements are used to continuously monitor each production zone and to update petroleum reservoir models. To make measurements to determine the rates of increase in temperature and pressure, the hole in the well closes and the measurements are continued. These prior art methods require transporting drilling cable tools to the site, which can be very costly for the hole in a well in the open sea and the hole in a well drilled in remote sites. The present invention highlights the deficiencies of the prior art described above, and provides an apparatus and methods that, in a preferred embodiment, use fiber optic sensors where each sensor can provide information about more than one parameter to perform a variety of functions. The sensors can be placed along any length of the hole in the well. The segments of the sensor, each segment containing one or more sensors, can be coupled to form a chain that can be arranged on the deck to continuously monitor the hole in the well. The sensors can be distributed in the hole of a well or the hole of multiple wells to determine the parameters of interest.

BRIEF DESCRIPTION OF THE INVENTION The present invention broadly comprises in a first embodiment, an apparatus for controlling the injection of chemical products from a system for treating production fluids of an oilfield using a device for injecting chemical products to inject one or more chemical products into the system of treatment. The system also includes at least one chemical sensor associated with the treatment system that communicates with a control and monitoring system to control, in real time, the chemical injection device in response, at least in part, to the chemical sensor information. In a second embodiment, the present invention is directed to an apparatus for controlling the injection of chemical products from a system for treating production fluids from the well of an oil field, which comprises a device for injecting chemical products to inject one or more chemicals in the production fluids in a drilling bottom site. In this mode, at least one drilling bottom sensor is provided which detects at least one property of the fluids produced from the oilfield well at the bottom of the drilling site, together with a control and monitoring system for control, in real time, the device for injecting chemicals in response, at least in part, to the information from the bottomhole sensor. The bottomhole sensor may be a chemical sensor or any other sensor that is suitable for use with the treatment system of the present invention. In a third embodiment, an apparatus for controlling the injection of chemical products from a system for treating production fluids from the well of an oil field, includes a device for injecting chemical products to inject one or more chemical products into the treatment system, and a plurality of sensors associated with and distributed along at least a portion of the treatment system. The sensors detect at least one parameter of the well fluids of the oil field, and communicate with a control and monitoring system that controls, in real time, the chemical injection device in response, at least in part, to the information of the plurality of sensors. In this mode, the 5 distributed sensors can be located at the bottom of the borehole or borehole, and the chemical injection device can inject the chemicals into a surface treatment system or into production fluids at a site of the drilling fund. The present invention uses sensors that can be located in the The bottom of the borehole, the borehole, the surface, or a combination thereof, and, in addition, the sensors can be provided as a plurality of sensors in a system distributed along the wellbore. Each sensor may be configured to provide multiple measurements, and a plurality of separate sensors may be arranged in the hole of the sensor. well. The sensors may comprise a fiber optic sensor in which a light source and a data acquisition and processing unit are preferably disposed at the bottom of the perforation. When the sensor of the present invention is a fiber optic sensor, a single light source can be used in a multilateral wellbore configuration. The sensors can be installed permanently in the hole of the well. The chemical parameters that can be measured by chemical sensors include, but are not limited to, specific chemical content, potential ionic content, # _ - * 9 V * ^ _ -rt_fe • < Sacks covalent content, pH level, oxygen levels, organic levels and organic precipitates. The distributed sensors of this invention find particular utility in the monitoring and control of various chemical products which are injected into the well. Such chemicals are required at the bottom of the perforation to reveal a large number of known problems such as inhibition of scale formation and various pretreatments of the fluid that is being produced. In accordance with the present invention, a system for monitoring and controlling the injection of chemical products, includes the placement of one or more sensors at the bottom of the borehole in the production area to measure the chemical properties of the fluid produced, as well as to measure other parameters of interest of the drilling fund. These sensors are preferably fiber optic based and are formed from a sun gel matrix, and provide a reliable and relatively inexpensive indicator of high temperatures of the desired chemical parameter. The chemical sensors at the bottom of the borehole can be associated with a network of distributed fiber optic sensors located along the hole in the well to measure pressure, temperature and / or flow characteristics. The surface controllers and / or bottom of the borehole are fed by several sensors from the bottom of the borehole and, in response to them, control the injection of chemicals into the borehole. By means of the sensors that communicate with the surface controllers and / or the bottom of the borehole, the efficiency of a surface treatment system or the bottom of the borehole is monitored in real time, and based on the information detected, the controllers they will initiate a certain change in the form, quantity or type of the chemical that is being injected. In yet another feature of this invention, the control and monitoring system and sensors associated therewith are used in a treatment system comprising a surface treatment having at least one sensor associated with the surface treatment system. The parameters related to the chemical that is being used in the surface treatment are measured in real time and online, and these measured parameters are used to control the dosage of chemicals in the surface treatment system. The surface treatment system uses one or more sensors that communicate with a control and monitoring system to control, in real time, a device for injecting chemical products. One or more chemical products are injected into the surface treatment system. When a surface treatment system is used to treat the well production fluids, the sensors can be distributed at the bottom of the hole, the mouth of the hole, or a combination thereof. The examples of the most important features of the invention have been summarized rather broadly so that the detailed description thereof which follows can be better understood, and so that the contributions to the art can be appreciated. In fact, there are other features of the invention that will be described below and that will form the subject of the appended claims thereto.

BRIEF DESCRIPTION OF THE DRAWINGS For a detailed understanding of the present invention, reference should be made to the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, in which like elements have been given similar numbers, and wherein: 1 is a schematic illustration of a chemical product injection monitoring and control system using a distributed sensor arrangement and sensor system for chemical monitoring of the bottom of the borehole in accordance with the present invention; Figure 2 shows a schematic illustration of a chemical product injection monitoring and control system using a distributed sensor arrangement where the sensors comprise, at least in part, fiber optic sensors in accordance with one embodiment of the present invention. invention; Figure 3 is a schematic illustration of a control and monitoring system for injecting chemical products of one embodiment of the present invention; Figure 4 is a schematic illustration of a fiber optic sensor system for monitoring the chemical properties of the fluids produced; Figure 5 is a schematic illustration of a fiber optic sol gel indicator probe for use with the sensor system of Figure 4; Figure 6 is a schematic illustration of a surface treatment system in accordance with the present invention; and Figure 7 is a schematic illustration of a control and monitoring system for the surface treatment system of Figure 6.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The concepts and applications of the present invention will be described in the first instance in relation to Figure 1, which shows schematic illustrations of a control system and monitoring of chemical products injection, in real time, using a distributed sensor arrangement and a sensor system for monitoring the bottom of the perforation according to an embodiment of the present invention. The sensors may be arranged in many other ways within the concepts described herein. Referring now to Figure 1, a system of distributed sensors 10 and sensor of the bottom of the bore 12 is provided and is particularly suitable for use in a production well 11, where chemicals are being injected therein, and there is the need resulting from the monitoring of said chemical injection process to optimize the use and effect of the injected chemical products. Frequently, the chemicals need to be pumped down into a production well 11 to inhibit the formation of scale, paraffins and the like, and for other known processing applications and the pretreatment of the fluids being produced. The chemicals are also introduced into the bottom of the drilling to function as emulsion breakers. Frequently, as shown in Figure 2, the chemicals are introduced into a ring 16 between the production pipe 18 and the cover 20 of the well 11. The chemicals can also be introduced into a capillary (not shown), whose use is known in the art. The injection of chemical products (shown schematically at 22) can be achieved in several known methods, such as in connection with a submersible pump (as shown, for example, in US Patent 4,582,131, assigned to the agent thereof and incorporated herein as a reference), or through an auxiliary line associated with a cable used with a submersible electric pump (as shown, for example, in U.S. Patent 5,528,824, assigned to the attorney thereof and incorporated herein) as reference). In accordance with one embodiment of the present invention, one or more sensors of the bottom of the drilling or drilling base 12 are located in the production zone to detect a variety of parameters associated with the production fluid and / or the interaction of the injected chemical and the production fluid. In this way, the sensors of the drill base will detect parameters regarding the chemical properties of the fluid produced, such as the potential ionic content, specific chemical content, covalent content, pH level, oxygen levels, organic precipitates, and measurements. Similar. The sensors 12 can also measure physical properties associated with the production fluid and / or the interaction of the injected chemicals and the production fluid, such as the oil / water fraction, the viscosity and the percentage of solids. Sensors 12 may also provide information regarding the accumulation of paraffin, corrosion and scale, H2S content, hydrate content, asphaltene dispersants, biocides, demulsifiers, and the like. Sensors 12 may include sensors to determine the resistivity of fluids and formations, gamma ray sensors and hydrophones. The measurements of the sensors 12 and a plurality of distributed sensors 10 that are located along at least a portion of the wellbore 14 (eg, preferably inside the production pipe 18), are combined to determine various conditions of the bottom of the hole. For example, flow measurements of production zones and resistivity measurements can be combined to determine water saturation or to determine oil, gas and water content. In one embodiment, sensors 12 are permanently installed in wellbore 14 at selected sites. In the hole of a production well 14, the sensors 12 provide continuously or periodically (as programmed), in real time, measurements of pressure and / or temperature and / or fluid flow. Said measurements are preferably made for each production zone in each of the wellbores 14. In order to carry out certain types of petroleum reservoir analysis, it is required to know the rates of increase in temperature and pressure in the wellbore. This requires measuring the temperature and pressure at selected sites at the bottom of the borehole for prolonged periods after closing well 11 on its surface. In the methods of the prior art, the well 11 is closed on its surface, and a drilling cable tool (not shown) is transported in the well hole 14 and placed at a site therein. The tool continuously measures the temperature and pressure, and can provide another measurement, such as flow control. These measurements are then used to carry out oil reservoir analyzes, which may include determining the level of hydrocarbon reserves remaining in a field, the fluid flow characteristics of the production formations, the water content, etc. . The prior art methods described above do not provide a continuous measurement in real time while the well is producing, and require special drilling cable tools that must be transported to the bottom of the bore. The present invention, on the other hand, provides on-site measurements while wellbore 14 is producing. The fluid flow information for each zone is used to determine the efficiency of each production zone. The decrease in flow rates over time indicates problems with flow control devices, such as screens and slip sleeves, or clogging of bores and presence of rock matrix near wellbore 14. This information is used to determine the course of action, which may also include opening or closing the sliding sleeves to increase or decrease the speed of • production, corrective work such as cleaning or reaming operations, 5 closing of a particular area, etc. Temperature and pressure measurements are used to continuously monitor each production zone and to update petroleum reservoir models. To make measurements to determine the rates of temperature and pressure increase, the well hole 14 is closed, and the measurements are continued. This does not require * ^ _ 10 transport the drilling cable tools to the site, which can be very costly for wellbore 14 in the open sea and wellbore 14 drilled in remote sites. In addition, on-site measurements and computed data can be communicated to a central office or to satellite profile and oil field engineering offices. This monitoring The continuous flow of each well hole 14 allows relatively fast actions to be taken, which can significantly improve the production of hydrocarbons and the life of the well hole 14. The measurements described above can also be taken for non-productive zones to facilitate modeling of oil deposits, to determine the effect of production of several wellbores 14 in the field in which the wellbore 14 is drilled. Although the present invention has been described above in relation to a single well hole 14, it is understood that it is within the scope of the invention that the apparatus and method of the present invention can be used in an oilfield facility, wherein a plurality of wellbores 14 are present. The present invention is also preferably associated with a surface monitoring and control system 24, and one or more known surface sensors 26 for detecting parameters related to the fluid produced; and more particularly to detect and monitor the effectiveness of the treatment produced by the injected chemicals. The sensors 26 associated with the surface system 24 can detect parameters related to the content and amount, for example, of hydrogen sulfide, hydrates, paraffins, water, solids and gases. Preferably, the production well 11 described in FIG. 2 has associated therewith the so-called "intelligent" control and monitoring system of the bottom of the borehole, which may include a computerized controller 28 from the bottom of the borehole and / or the surface control and monitoring system 24 mentioned above. This control and monitoring system 28 is of the type described in the patent 5,597,042, which is assigned to the agent thereof and is fully incorporated herein by reference. As described in the '5,597,042 patent, the sensors of the "intelligent" production wells of this type are associated with computer controllers of the bottom of the borehole and / or surface which receive information from the sensors, and based on this information, initiate some kind of control to increase or optimize the production efficiency of the well 11, or in some other way, effecting the production of fluids from the formation.

In the present invention, the surface and / or bottom drilling computers 24, 28 will perform the monitoring of the effectiveness of the treatment of the injected chemical products, and based on the information detected, the control computer will initiate a change in the form, quantity or type of chemical that is being injected. For example, if the sensor 10 and / or 12 indicates that the pH level is not within a desired range, this information is communicated with the surface and / or bottom drilling computers 24, 28, and the device. Injection of chemicals 22 injects one or more chemicals in response, at least in part, to the information from sensors 10 and / or 12. In the system of the present invention, the sensors 10 and 12 can be connected remotely or in situ. In a preferred embodiment of the present invention, the sensors of the perforation base 12 comprise chemical sensors, and more particularly chemical sensors of optical fiber. Such fiber optic chemical sensors preferably use fiber optic probes that are used as a sample interface to allow light from the optical fiber to interact with the liquid or gas stream and return to a spectrometer for measurement. The probes are typically composed of sun gel indicators. The sun gel indicators allow online measurements in real time and control through the use of indicator materials trapped in a porous glass matrix derived from sun gel. Thin films of this material are coated on the optical components of various probe designs to create sensors for environmental and processing measurements. These probes provide improved sensitivity to chemical species based on the characteristics of the specific indicator. For example, sun gel probes can measure the pH of a material with great precision, and the sun gel probes can also measure the specific chemical content. The sun gel matrix is porous, and the size of the pores is determined by how the glass is prepared. The sun gel process can be controlled to create a mixed sun gel indicator material with pores small enough to trap an indicator in the matrix, but large enough to allow ions of a particular chemical of interest to enter and exit freely and react with the indicator. An example of a sun gel indicator suitable for use in the present invention is shown and described in relation to FIGS. 4 and 5. The concepts and applications of one embodiment of the present invention will be described with reference to FIG. 2, FIG. which shows schematic illustrations of the placement and use of fiber optic sensors and other sensors 30 in accordance with certain embodiments of the present invention. The sensors 30 may be arranged in many other ways within the concepts described herein. One or more fiber optic sensors 30 are used, wherein each sensor 30 can be operated in one or more of a way, each mode providing a measurement of a different parameter of interest. For example, the same fiber optic sensor 30 may be configured to provide one or more measurements selected from a group consisting of drilling bottom temperature, bottomhole pressure, fluid flow and acoustic signals. To obtain multiple measurements of the same fiber optic sensor 30, the sensor 30 is configured to operate in multiple modes, which can be selectively activated during operations, thereby obtaining multiple measurements. Said fiber optic sensor 30 is commercially available from CIDRA, of Wallingford, Connecticut. Figure 2 shows an example of a main well hole 14 formed from the land surface 13. For purposes of illustration, the well hole 14 hereof is shown drilled from the ground; however, this invention is equally applicable to offshore wellbores (not shown). It should be noted that all of the wellbore configurations 14 shown and described herein are to illustrate the present invention, and should not be considered to limit the inventions claimed herein. In one application, a number of fiber optic sensors 30 is placed in the wellbore 14. A plurality of fiber optic chains or segments, or an individual fiber optic chain or segment, each segment containing a plurality of fiber sensors. Separate optics 30 may be used to install the desired number of fiber optic sensors 30 in the bore hole 14. As an example, FIG. 2 shows two segments 32 and 34 coupled in series, each containing a plurality of fiber sensors. 30 optics separated. A source and light detector (LS / D) 36 coupled to an end 38 of the segment 32 are arranged in the well hole 14 to transmit the light energy to the sensors 30 and to receive the reflected light energy from the sensors 30. A data acquisition and processing unit (DA) 40 is disposed at the bottom of the bore to control the operation of the sensors 30, process the sensor signals and data from the bottom of the borehole and to communicate with other equipment and devices, including devices in hole 5 of hole 14 or on the surface (not shown). Alternatively, a light source 42 and the data acquisition and processing unit 44 may be located on the surface 15. Similarly, fiber optic sensors 30 may be arranged in other well holes that are present in the reservoir. petroleum Alternatively, light sources can be used and • 10 multiple units of data acquisition at the bottom of the hole, on the surface or in combination. Since the same sensor can take different types of measurements, the data acquisition unit 40 or 44 is programmed to multiplex the measurement. Multiplexing techniques are known in the art, so they are not described in detail here. The data acquisition unit 15 can be programmed to control the sensors of the ^ bottom of drilling 30 independently or after receiving control signals from the surface, or a combination of these methods. The sensors 30 can be installed in the wellbore 12 before or after installing the covers in the wellbore, such as the cover 20 shown installed in the bore hole 14. This can be achieved by joining the chains 32 and 34 along the inside of the cover 20. In said method, the chains 32 and 34 are preferably attached end-to-end in the surface to secure the proper connections of the couplings 52. The fiber optic sensors 30 and / or the chains 32 and 34 can be hff? l'splegar or installed by robotic devices (not shown), which are known in the art. Alternatively, the fiber optic sensors 30 may be placed on the cover 20 on the surface, while the individual cover sections (which are typically around 12.2 m in length) are joined before transporting the cover sections. in the well holes. Plugging techniques for joining casing or pipe sections and known in the art to rotary joints are preferred, because plugging generally provides better alignment of the terminal couplings 52 and also because it allows operators to test and inspect the optical connections between the segments for the proper bidirectional transmission of the light energy through the complete chain 32, 34. Thus, in the system described in Figure 2, a plurality of fiber optic sensors 30 are installed separately in one or more well holes, such as the well hole 14. If desired, each fiber optic sensor 30 it can operate in more than one way to provide a number of different measurements. The light source 36 and the data acquisition and detection system 40 are preferably located at the bottom of the perforation. Although each fiber optic sensor 30 provides measurements for multiple parameters, it is comparatively small compared to individual commonly used single measurement sensors, such as pressure sensors, strain gauges, temperature sensors, flow measurement devices and acoustic sensors. , which allow to make a large number of different types of measurements using a relatively small space at the bottom of the hole. The installation of devices or units of acquisition and processing of data 40, allows to make a large number of calculations and data processing in the bottom of the hole, avoiding the need to transmit large amounts of data to the surface. The installation of the light source 36 at the bottom of the perforation allows the source 36 to be located close to the sensors 30, which avoids transmitting light at great distances from the surface 15. The data of the acquisition system 40 from the bottom of the perforation They can be transmitted to the surface by any suitable method including wired connections, electromagnetic telemetry and acoustic methods. Still, in some applications, it may be convenient to locate the light source 36 and / or the data acquisition and processing system 44 on the surface. Also, in some cases, it may be more advantageous to partially process the data at the bottom of the borehole and partially on the surface. With reference to Figures 1 and 2, any number of other sensors, generally denoted herein by the number 60, may be disposed in the wellbore 14. Said sensors 60 may include sensors for determining the resistivity of fluids and formations, gamma ray sensors and hydrophones. The measurements of the fiber optic sensors 30 and the sensors 60 are combined to determine the different conditions at the bottom of the borehole.

With reference to Figure 3 illustrating an additional feature of the present invention and comprising a treatment system 100 having the plurality of distributed sensors 10 located along at least a portion of the wellbore 14, at least one distributed sensor 102 is located upstream of the chemical injector 22 and at least one distributed sensor 104 is located downstream from the point of chemical addition in the chemical injector 22. The chemical addition site may be located at a site along the well hole 14 as illustrated in Figure 3, it being understood that the positioning of the chemical addition point by the chemical injector 22 in Figure 3 is for illustration and not for limitation. The chemicals are introduced into the well hole 14 by an injection duct 21, or by other suitable means known in the art. Referring to Figures 4 and 5, a probe is shown at 216 connected to an optical fiber cable 218 which in turn is connected to a light source 220 and a spectrometer 222. As shown in Figure 5, the probe 216 includes a sensor housing 224 connected to a lens 226. The lens 226 has a sun gel coating 228 thereon, which is adapted to measure a specific parameter of the bottom of the perforation such as the pH, or is selected to detect the presence, absence or quantity of a particular chemical such as oxygen, H2S, or the like. Fixed to, and separated from, the lens 226, is a mirror 230. During use, the light of the optical fiber cable 218 is aligned by the lens 226, after which the light passes through the sun gel coating 228. and the sample space 232. The light is then reflected by the mirror 230 and returned to the fiber optic cable. The light transmitted by the fiber optic cable is measured by the spectrometer 222. The spectrometer 222 (as well as the light source 220) can be located on the surface or somewhere on the bottom of the perforation. Based on the measurements of the spectrometer, a control computer 214, 216 will analyze the measurement, and based on this analysis, the chemical injection apparatus 208 will change the amount (dosage and concentration) and speed or type of product chemical that is being injected into the bottom of the well drilling. The information of the chemical injection apparatus regarding the amount of chemical left in storage, the level of quality of the chemical product, and the like, will also be sent to the control computers. The control computer may also base its control decision on the power received from the surface sensor 215 with respect to the effectiveness of the chemical treatment on the produced fluid, the presence and concentration of any impurities or inconvenient by-products, and the like. Referring again to FIGS. 1 and 2, in addition to the sensors of the perforation base 12 which are formed of the sensors of the fiber-optic sol gel type, the sensors 10 distributed along the production line 18 can also include the optical fiber 30 sensors (sun gel indicators) of the type described above. In this way, the chemical content of the production fluid can be monitored as it travels to the production pipeline 18, if that is convenient. The permanent placement of sensors 10, 12 and the system of • Control 28 at the bottom of the well drilling leads to a significant advance in the field, and allows real-time remote monitoring of injections of chemical products into the well, without the need for the drilling cable device or other interventions in the well. In accordance with another embodiment of the present invention, a novel control and monitoring system is provided for use in connection with • 10 a treatment system to manipulate hydrocarbons produced in an oilfield. Referring to Figure 6, a typical surface treatment system used to treat fluids produced in oil fields is shown. As is well known, the fluid produced from the well includes a combination of emulsion, oil, gas and water. After these fluids the wells are produced to the surface, they are contained in an oil pipeline known as a "flow line". The flow line can vary in length from • a few feet up to several thousand feet. Typically, the flow line is directly connected to a series of tanks and treatment devices that have the purpose of providing the separation of water in oil emulsion and the gas. In addition, it is intended that oil and gas be separated for transport to the refinery. The fluids produced that flow in the flow line and the different separation techniques that act on these produced fluids, lead to important corrosion problems. Currently, the measurement of the corrosion rate in the different metallic components of the treatment systems such as pipes and tanks, is carried out by means of a number of • sensor techniques including weight loss coupons, electric resistance probes, electrochemical-linear polarization techniques, electrochemical noise techniques, and AC impedance techniques. Although these sensors are useful for measuring the corrosion rate of a metal pipe or container, these sensors do not provide any information regarding the chemicals themselves, ie the concentration, characterization or other • 10 parameters of the chemical products introduced in the treatment system. These chemicals are introduced for several reasons including inhibition of corrosion and disintegration of the emulsion, as well as the control of scale, wax, asphaltene, bacteria and hydrates. In accordance with an important characteristic of this In accordance with the invention, the sensors are used in chemical treatment systems of the type described in Figure 6, which monitor the chemicals themselves as opposed to the effects of the chemicals (e.g., the rate of corrosion). These sensors provide the operator of the treatment system with a real-time knowledge of the amount of chemical product that is being introduced, the transport of that chemical throughout the system, the concentration of the chemical in the system, and similar parameters. Examples of suitable sensors that can be used to detect parameters with respect to chemicals traveling through the treatment system include a chemical sensor, such as the fiber optic sensor described above with reference to Figures 4 and 5, as well as other known sensors, such as sensors based on a variety of technologies including ultrasonic absorption and reflection, laser-heated cavity spectroscopy (LIMS), X-ray fluorescence spectroscopy, neutron activation spectroscopy, pressure measurement, absorption or reflectance by microwave or millimeter wave radar, and other optical and acoustic methods (ie, ultrasonic or sonar). A microwave sensor suitable for detecting moisture and other constituents in the effluent and liquid and solid phase effluent streams is described in the U.S. patent. No. 5,455,516, the contents of which are incorporated herein by reference. An example of an apparatus suitable for detection using LIBS is described in the US patent. No. 5,379,103, the contents of which are incorporated herein by reference. An example of a suitable apparatus for detecting LIMS is the LASMA laser mass analyzer, available from Advanced Power Technologies, Inc., of Washington, D.C. An example of a suitable ultrasonic sensor is described in the U.S.A. 5,148,700 (whose contents are incorporated herein by reference). A commercially available suitable acoustic sensor is marketed by Entech Design, Inc., of Denton, Texas, under the trade name of MAPS®. Preferably, the sensor is operated at a multiplicity of signal frequencies and intensities. Suitable millimeter wave radar techniques used in conjunction with the present invention, are described in Chapter 15 of Principles and Applications of Millimeter Wave Radar, edited by N. C. Currie and C. E. Brow ?, Artecn House, Nor ood, MA 1987. The ultrasonic technology cited above can be extended logically to millimeter wave devices. Although the sensors can be used in a system such as that shown in Figure 6 at a variety of sites, the arrows indicated by numbers 300 to 316 indicate the positions where the information regarding the introduction of chemicals would be especially Useful. Referring now to Figure 7, the surface treatment system of Figure 6 is generally shown at 320. In accordance with the present invention, the chemical sensors (ie, 300 to 316) will detect, in real time, parameters ( that is, concentration and classification) with respect to the chemicals introduced, and will supply the detected information to a 322 controller (preferably a computer-based or microprocessor-based controller). Based on the detected information monitored by the controller 322, the controller will instruct a pump or other measuring device 322 to maintain, vary or otherwise alter the amount of the chemical and / or the type of chemical that is present. being added to surface treatment system 320. The chemical supplied from tanks 326, 326N and 3260 may, in fact, comprise any suitable treatment chemicals such as chemicals used to treat corrosion, break emulsions, etc. . Examples of suitable corrosion inhibitors include aminidiazolines or long chain amines. Suitable commercially available chemicals include Cronox ™, which is a corrosion inhibitor marketed by Baker Petrolite, a division of Baker-Hughes, Incorporated, of Houston, Texas. In this way, in accordance with the control and monitoring system of Figure 7, based on the information provided by the chemical sensors 300 to 316, corrective measurements can be made in real time to vary the injection of the chemical product (inhibitor). of corrosion, emulsion breakers, etc.) in the system. The point of injection of these chemicals could be any point upstream of the site that is being detected, such as the site where the corrosion is being detected. In fact, this injection point could include injections at the bottom of the perforation. In the context of a corrosion inhibitor, the inhibitors work by forming a protective film on the metal, and thus prevent water and corrosive gases from corroding the metal surface. Other surface treatment chemicals include emulsion breakers, which disintegrate the emulsion and facilitate the removal of water. In addition to removing or breaking emulsions, chemical products are also introduced to break and / or remove solids, wax, etc. Typically, chemicals are introduced to provide what is known as a base sediment and water (B.S. and W.) of less than 1%. In addition to the parameters regarding the introduction of chemical products that are being detected by the chemical sensors 300 to 316, the control and monitoring system of the present invention can also use known corrosion measuring devices, as well as speed sensors. flow, temperature and pressure. These other sensors are shown schematically in Figure 7 at 328 and 330. The present invention thus provides in one embodiment, means for measuring parameters with respect to the introduction of chemicals into the system, in real time and online. 5 As mentioned, these parameters include concentrations of chemical products and may also include chemical properties such as measurements of potential ion content, covalent content, pH level, oxygen levels, organic precipitates, and similar measurements. Also, you can measure the viscosity of the oil / water fraction and the percentage of solids, as well as well as the accumulation of paraffin and scale, H2S content, and the like. Although the preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Therefore, it will be understood that the The present invention has been described by way of illustration and not as a limitation. & * "

Claims (26)

NOVELTY OF THE INVENTION CLAIMS •

1. An apparatus for controlling the injection of chemical products from a system for treating production fluids from the well of an oil field, characterized in that it comprises: a device for injecting chemical products that injects one or more chemical products into the system of treatment; at least one chemical sensor associated with the system 10 treatment that detects at least one chemical property of the fluids from the oilfield well; and a control and monitoring system to control, in real time, the device for injecting chemical products in response, at least in part, to the chemical sensor information.

2. The apparatus according to claim 1, characterized 15 also because the chemical sensor is located at the bottom of the well borehole to detect at least one chemical property of the fluids produced from the well.

3. The apparatus according to claim 1, further characterized in that the control and monitoring system comprises a system of 20 monitoring located on the surface, monitoring the effect of the treatment by injected chemical products on the fluids produced, and a control system that receives power from the monitoring system.

4. - The apparatus according to claim 1, further characterized in that it includes at least one additional sensor distributed in the treatment system to measure at least one of pressure, temperature and flow, the additional sensor communicating with the control and monitoring system .

5. The apparatus according to claim 1, further characterized in that it includes a plurality of chemical sensors, the sensors being distributed along a portion of the length of the well.

6. The apparatus according to claim 5, further characterized in that the distributed sensors comprise optical fiber sensors.

7. The apparatus according to claim 2, further characterized in that the chemical sensor of the bottom of the perforation is a fiber optic sensor having a probe which is sensitive to at least one chemically related selected property, and the probe includes a sun gel sensor.

8. The apparatus according to claim 1, further characterized in that the chemical sensor detects a parameter selected from the group consisting of oxygen levels, pH level, content of organic precipitates, specific chemical content, covalent content, potential ionic content , oil / water fraction, viscosity, paraffin accumulation, build-up of scale, H2S content, hydrate content, corrosion accumulation, demulsifier content, asphaltene content and biocide content.

9. - The apparatus according to claim 1, further characterized in that the treatment system comprises: a surface treatment system for the well of an oil field.

10. The apparatus according to claim 9, further characterized in that the chemical injection device injects one or more chemical products into the surface treatment system for the treatment of the fluids produced in the well of an oilfield.

11. The apparatus according to claim 9, further characterized in that it includes at least one additional sensor distributed in the surface treatment to measure at least one of pressure, temperature and flow, the additional sensor communicating with the control system and monitoring.

12. The apparatus according to claim 11, further characterized in that the additional sensor comprises at least one fiber optic sensor.

13. An apparatus for controlling the injection of chemical products from a system for treating production fluids from the well of an oil field, further characterized by comprising: a device for injecting chemical products that injects one or more chemical products into the fluids of an oilfield. production on a drilling bottom site; at least one sensor from the bottom of the borehole that detects at least one property of the fluids produced from the oilfield well at a site at the bottom of the borehole; and a control and monitoring system to control, in real time, the chemical injection device in response, at least in part, to the sensor information of the bottom of the borehole.

14. The apparatus according to claim 13, further characterized in that the sensor of the bottom of the hole is located at the bottom of the hole of the well to detect at least one chemical property of the fluids produced from the well.

15. The apparatus according to claim 13, further characterized in that the sensor of the bottom of the perforation is a chemical sensor.

16. The apparatus according to claim 13, further characterized in that the control and monitoring system comprises a monitoring system located on the surface, monitoring the effect of the treatment by the chemicals injected on the fluids produced, and a system of control that receives power from the monitoring system.

17. The apparatus according to claim 13, further characterized in that the sensor of the bottom of the perforation detects a parameter selected from the group consisting of oxygen levels, pH level, content of organic precipitates, specific chemical content, covalent content , potential ionic content, oil / water fraction, viscosity, paraffin accumulation, scale accumulation, H2S content and hydrate content.

18. - The apparatus according to claim 13, further characterized in that it includes a plurality of sensors, the sensors being distributed along a portion of the length of the well.

19. An apparatus for controlling the injection of chemical products from a system for treating production fluids from the well of an oil field, further characterized by comprising: a device for injecting chemical products that injects one or more chemical products into the system of the treatment; a plurality of sensors associated with, and distributed along at least, a portion of the treatment system that detects at least one parameter of the well fluids from the oil field; and a control and monitoring system for controlling, in real time, the device for injecting chemical products in response, at least in part, to the information of the plurality of sensors.

20. The apparatus according to claim 19, further characterized in that the sensor is located at the bottom of the well bore to detect at least one chemical property of the fluids produced from the well.

21. The apparatus according to claim 20, further characterized in that the chemical property is selected from the group consisting of oxygen levels, pH level, content of organic precipitates, specific chemical content, covalent content, potential ionic content, oil / water fraction, viscosity, paraffin accumulation, scale accumulation, H2S content and hydrate content.

22. - The apparatus according to claim 19, further characterized in that the sensor is located at the wellhead.

23. The apparatus according to claim 19, further characterized in that the chemical product injection device 5 injects one or more chemicals into the bottom of the bore in response to the control and monitoring system.

24. The apparatus according to claim 19, further characterized in that the treatment system comprises a surface treatment system, wherein the product injection device 10 chemists inject one or more chemicals into the surface treatment system in response to the monitoring and control system.

25. The apparatus according to claim 19, further characterized in that it includes a plurality of sensors, the sensors being distributed along a portion of the length of the well. 15 26.- A method for monitoring and controlling the injection of chemical products in a system for treating the production fluids of an oil field using the apparatus according to claim 1.