REMOTE AND AUTONOMOUS CHEMICAL TREATMENT SYSTEM FOR APPLICATION IN PRODUCING WELLS OF OFFSHORE PLATFORMS

Abstract

The present invention addresses to a remote and autonomous chemical treatment system for application in producing wells of offshore platforms aiming at treatments for removal and prevention of production string fouling, selective completion system, well safety equipment (DHSV, HFIV) and rock formation. The purpose of this invention is to completely replace the stimulation boat, thus allowing treatments to be carried out with resources from the routine operational contracting of the offshore production unit.

Claims

1- A REMOTE AND AUTONOMOUS CHEMICAL TREATMENT SYSTEM FOR APPLICATION IN PRODUCING WELLS OF OFFSHORE PLATFORMS, characterized in that it comprises a tank (4) in which there are injected the scale inhibitor or other chemical product (1), industrial water (2), diesel (3), where through the pumping unit (5) it takes the prepared fluid through chicksan lines (6) to the intake of the PIG receiver or launcher (7) and injects the prepared cushion into the lift gas line (8) or into the production line (9), which through the production string (13) and valves of the Christmas tree (10), the prepared cushion is injected by “bullheading” through the perforations (15) in the reservoir rock (16).

2- THE REMOTE AND AUTONOMOUS CHEMICAL TREATMENT SYSTEM FOR APPLICATION IN PRODUCING WELLS OF OFFSHORE PLATFORMS according to claim 1, characterized in that there is the adaptation and use of facilities of the offshore production unit of the diesel and industrial water systems to carry out chemical treatment of wells without assistance from stimulation vessels.

3- THE REMOTE AND AUTONOMOUS CHEMICAL TREATMENT SYSTEM FOR APPLICATION IN PRODUCING WELLS OF OFFSHORE PLATFORMS according to claim 1, characterized in that is uses chemical products in the treatment of production strings, subsea line systems and reservoir rock.

4- THE REMOTE AND AUTONOMOUS CHEMICAL TREATMENT SYSTEM FOR APPLICATION IN PRODUCING WELLS OF OFFSHORE PLATFORMS according to claims 1 and 3, characterized in that is uses scale inhibitors, scale removers, chemical diverter or damage controllers.

5- THE REMOTE AND AUTONOMOUS CHEMICAL TREATMENT SYSTEM FOR APPLICATION IN PRODUCING WELLS OF OFFSHORE PLATFORMS according to claim 1, characterized in that there is the continuous or batch injection of chemical products.

6- THE REMOTE AND AUTONOMOUS CHEMICAL TREATMENT SYSTEM FOR APPLICATION IN PRODUCING WELLS OF OFFSHORE PLATFORMS according to claim 1, characterized in that it is applied to producing rock formations and fluid composition and taking advantage of chemical products already in use in the offshore unit, such as demulsifiers, asphaltene inhibitors, corrosion inhibitors, chemical diverter, damage controllers or a chemical soluble in industrial water or treated injection water.

7- THE REMOTE AND AUTONOMOUS CHEMICAL TREATMENT SYSTEM FOR APPLICATION IN PRODUCING WELLS OF OFFSHORE PLATFORMS according to claim 1, characterized in that it is adapted for the treatment of injector offshore wells to remove damage with remote acidification, by altering the interconnection of the remote and autonomous chemical treatment for the water injection system.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0015] The present invention will be described in more detail below, with reference to the attached figures which, in a schematic form and not limiting the inventive scope, represent examples of its embodiment. In the drawings, there is:

[0016] FIG. 1 illustrating a schematic drawing of a system with LGL injection according to the present invention, where there are represented: (1) chemical product container, (2) industrial water intake, (3) diesel intake, (4) pumping unit tank, (5) pumping unit, (6) chiksan lines, (7) PIG launcher/receiver, (8) gas lift line/well production line, (9) well production line, (10) well wet Christmas tree, (11) mudline, (12) well annular, (13) well production string, (14) gas lift valve, (15) perforations, and (16) reservoir.

DETAILED DESCRIPTION OF THE INVENTION

[0017] The remote and autonomous chemical treatment system according to the present invention and illustrated in FIG. 1 allows the adaptation and use of facilities of the offshore production unit of industrial water or treated injection systems, and diesel both available in routine operations of the offshore unit to carry out chemical treatment of wells without the assistance of stimulation vessels.

[0018] As can be seen in FIG. 1, in the tank (4), there are injected, depending on the type of treatment to be performed in the subsea production system (treatment of production strings, subsea line systems and reservoir rock), the scale inhibitor and/or other water soluble chemical products (scale remover—acids or chelators; chemical diverter or damage controllers), (1), industrial or injection water (water intake—2) for preparing the aqueous cushion treatment and displaced with diesel (diesel intake —3).

[0019] The pumping unit (5) takes the prepared fluid through chicksan lines (6) to the intake of the PIG receiver or launcher (7) and injects the prepared cushion continuously or in batches into the gas lift line (8) or in the production line (9), depending on the available alignment. Through the production string and valves of the Christmas Tree (10), the prepared cushion is injected by “bullheading” through the perforations (15) in the reservoir rock (16).

[0020] The system of the present invention can be applied to producing rock formations and fluid composition, taking advantage of the chemical products already in use in the offshore unit, such as demulsifiers, asphaltene inhibitors, corrosion inhibitors, chemical diverter, damage controllers or chemical product soluble in industrial water or treated injection water.

[0021] In addition, the system of the present invention can be adapted for treatment of offshore injection wells for damage removal with remote acidification, by changing the interconnection of the remote and autonomous chemical treatment system to the water injection system.

EXAMPLES

[0022] The following examples are presented in order to more fully illustrate the nature of the present invention and the manner of practicing the same, without, however, being considered as limiting its content.

Example 1: Procedure with Scale Inhibitor

[0023] Well operating by gas lift; pumping the cushions preferably at the maximum possible flow rate; required volume of diesel: ˜1,600 bbl (190.78 m.sup.3); required volume of industrial water: ˜1,000 bbl (119.24 m.sup.3); required volume of inhibitor: 1,000 liters.

[0024] With the offshore injection lines filled with diesel, align the system to the wellhead, via the production header, the service line interconnected via the chicksan line to the treatment cushion preparation tank.

[0025] Pressurize the lines with industrial water and prepare the cushion batch with inhibitor (addition of the inhibitor to the tank water). Align the treatment cushion through the service line to the wellhead (via the pig receiver) and proceed with the treatment injection.

[0026] Repeat the treatment injection batch if necessary. Carry out all displacement of aqueous fluid to rock formation to prevent hydrate/meet well integrity restriction with diesel pumping.

Example 2: Economic Valuation for Autonomous Removals and Inhibitions

[0027] Table 1 presents a comparison of costs per operation using rig/boat and autonomous treatment, where there is a large total reduction of costs resulting from autonomous treatments when compared to treatments using rig and stimulation boat.

TABLE-US-00001 TABLE 1 Calculation of NPV (Net Present Value). NPV in US$ NPV/TREAT R/C NPV/TREAT R/C millions Rig and Boat Autonomous treatments Removal 3.57 1.34 4.32 1.44 Removal and 0.92 1.25 2.78 2.50 inhibition TOTAL 4.49 2.59 7.10 3.94 Key: TREAT = treatment.

[0028] Table 1 reports the cost/benefit ratio in terms of saving the value of barrels of oil considering the relationship with conventional treatment (rig and boat) and the use of an autonomous treatment by the offshore production unit. For the case of autonomous removal and inhibition, there is a 100% return compared to a conventional treatment (double the value of the return to cost ratio—R/C).

[0029] It should be noted that, although the present invention has been described in relation to the attached drawings, it may undergo modifications and adaptations by technicians skilled on the subject, depending on the specific situation, but provided that it is within the inventive scope defined herein.