SYSTEM FOR UNBLOCKING OR CLEANING DUCTS BY MEANS OF A CONTROLLED LOCAL REACTION

Abstract

The present invention proposes the use of a tool (13) that is connected to a device for locomotion, such as, for example, a robot, and provided with an umbilical cable (06) to bring about a controlled reaction near the blockage, in order to remove it. In order to carry out that controlled reaction, an injection, and control system is used, which may be a closed loop control system.

Claims

1. A system for unblocking or cleaning ducts by means of a controlled local reaction, wherein it is a closed loop control system of a tool capable of allowing a controlled reaction to take place near a blockage, for that purpose using a robot-type equipment comprising control valves to clean or remove one or more obstructions from inside one or more lines, and with a controlled injection of the flow of Solution A and Solution B, which move to a reactor.

2. The system for unblocking or cleaning ducts by means of a controlled local reaction of claim 1, wherein it comprises control valves present on the robot-type equipment that block the discharge of Solutions A and B when the reaction gets out of control.

3. The system for unblocking or cleaning ducts by means of a controlled local reaction of claim 2, wherein Solutions A and B are two components which, when working together, create an exothermic reaction.

4. The system for unblocking or cleaning ducts by means of a controlled local reaction of claim 1, wherein it includes a temperature sensor or sensors close to the unblocking system.

5. The system for unblocking or cleaning ducts by means of a controlled local reaction of claim 1, wherein the tool presents a closed loop temperature control in which the temperature value read on the temperature sensor is directed to a controller that adjusts the discharge from pumps.

6. The system for unblocking or cleaning ducts by means of a controlled local reaction of claim 1, wherein the reactor has configurations selected from the group consisting of a random configuration, labyrinth, and baffles.

7. The system for unblocking or cleaning ducts by means of a controlled local reaction of claim 1, wherein it comprises a diffusor for discharge of the fluids to the one or more lines.

8. The system for unblocking or cleaning ducts by means of a controlled local reaction of claim 7, wherein said diffusor has configurations selected from the group consisting of a concentrated diffusor and a homogeneous diffuser.

9. The system for unblocking or cleaning ducts by means of a controlled local reaction of claim 8, wherein it comprises pressure and temperature sensors, and a hall sensor, the hall sensor configured to identify the contact with the one or more obstructions.

10. The system for unblocking or cleaning ducts by means of a controlled local reaction of claim 1, wherein the one or more obstructions comprise hydrate or paraffin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be described in greater detail below, with reference to the attached drawings, which in a manner not limiting to the inventive scope, represent a preferential embodiment of execution. Therefore:

[0014] FIG. 1 presents an overview of undersea production systems and of the system proposed by the present invention.

[0015] FIG. 2 presents an overview of the unblocking system proposed by the present invention;

[0016] FIG. 3 presents different configurations for the reactor of the present invention;

[0017] FIG. 4 presents different configurations for the diffusor of the present invention; and

[0018] FIG. 5 presents an optional configuration for the system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0019] For the purposes of the present invention, undersea wells (01) are interconnected to Stationary Production Units (SPUs) (03) through rigid or flexible ducts (02). Additionally, those units (03) may be interconnected to other units or to stations on land, also by rigid or flexible ducts (02). Those ducts may eventually be restricted or blocked (04), preventing normal production or the transfer of fluids. That system is shown in detail in FIG. 1.

[0020] To eliminate that blockage in a controlled manner, a system that extends from the SPU is used (11), passing inside the umbilical (12) and going to the tool (13). On the SPU (11), there is at least one reservoir for Solution A (14), and optionally other reservoirs for other solutions, such as, for example, a reservoir for Solution B (15). That optional configuration with two fluids is the solution shown in detail in FIG. 2.

[0021] Additionally, there is a pump for Solution A (16) and a pump for Solution B (17). Those pumps allow fluids to be injected in a controlled manner. In the umbilical, each solution is moved by a hydraulic line, Solution A through one line (18) and Solution B through another (19) in the same umbilical. On the robot, control valves allow the injection of Solution A (20) and Solution B (21), or they reach the blockage. The released solution or the released solutions are moved to the reactor (22), where they eventually react. They then pass through a retention valve (23), which prevents the entry of fluid from the line to be unblocked, to inside the reactor. Next, they pass through the diffusor (53), which allows the fluids to exit the line.

[0022] The reactor (22), according to the present invention, may assume various configurations, such as, for example, a random configuration (31), labyrinth (32) or a baffle configuration (33), as shown in FIG. 3.

[0023] The diffusor (53) according to the present invention, may also assume different configurations, such as, for example, a concentrated diffusor (41) and a homogeneous diffusor (42), as shown in FIG. 4.

[0024] FIG. 5 shows an optional configuration for the system, with the lines reaching a labyrinth-type reactor (51). From the reactor, the system passes through the retention valve (52) and exits through the diffusor (53) At FIG. 5 we also see pressure and temperature sensors (54), and a hall sensor (56), which is a sensor to identify a contact with the obstruction.

[0025] Note that the present invention proposes the use of a tool (13), connected to a locomotion device, for example, a robot, with an umbilical cable (06). That tool will provide a controlled reaction near the obstruction in order to cause its removal, using an injection and control system to generate the controlled reaction.

[0026] Solutions A and B used in the present invention may be two components which, working together, generate a highly exothermic reaction, such as, for example, sodium nitrite and ammonium chloride in an acid medium. In this condition, upon reacting the components release heat, allowing dissolution of the hydrate after removing it from its stability envelope. It may also dissolve the paraffin, by taking the temperature to values above the crystal appearance start temperature (TIAC). As there are two pumps (16 and 17) and two valves (20 and 21) to independently control the discharge from the components, the process may be controlled through the use of sensors near the unblocking system, thus avoiding loss of control of reactions, and possible damage to the line that is to be unblocked. This prevents, for example, polymer layers from the flexible line (02) from breaking down.

[0027] The present invention may also be used to perform other reactions in a controlled manner inside tubing. Such reactions may be used, in addition to cleaning operations, for controlled injection of corrosion inhibitors, foaming agents, anti-foaming agents, etc.

[0028] The reactor (22) may assume different configurations, such as, for example, a random packing configuration (31), baffle (32), or labyrinth (33). In the last case, sequential labyrinths may be used to increase the effectiveness of the mixture and to reduce the reaction time. The diffusor (24) may also assume different configurations, such as, for example, a concentrated diffusor (41) and a homogeneous diffusor (42). The system may optionally have an associated system to identify the obstruction, for example through a spring, and it alters the position of the sensor hall (56). That alteration in the position of the sensor hall alters the magnetic flow over it and indicates the presence of the obstruction. The system may also optionally have an impact-buffering system (55) arising from release of the pressure confined by the obstructions.

[0029] Note that the above-mentioned system was tested in a laboratory. The test consisted of continuous pumping of two solutions of sodium nitrate and ammonium chloride in a tube cooled to 4° C. During that test, the components reacted and heated the region in a controlled manner, allowing a significant increase in temperature.

[0030] It should be noted that despite the present invention having been described in relation to the attached drawings, it may undergo modifications and adaptation by technicians versed in the matter, depending on the specific situation, but as long as it is within the inventive scope defined herein.