US3471174A

US3471174A - Ballistic jacket-pile connection

Info

Publication number: US3471174A
Application number: US651072A
Authority: US
Inventors: William F Manning
Original assignee: Mobil Oil Corp
Current assignee: ExxonMobil Oil Corp
Priority date: 1965-09-23
Filing date: 1967-03-30
Publication date: 1969-10-07
Anticipated expiration: 1986-10-07

Description

Oct. 7, 1969 w. F. MANNING 3,471,174

' BALLISTIC JACKET-FILE CONNECTION Original Filed Sept. 25, 1965 2 Sheets-Sheet 1 FIG. I

' INVENTORV WILLIAM E MANNING ATTORNEY w F. MANNING BALLISTIC JACKET-FILE CONNECTION Original Filed Sept. 23, 1965 Oct. 1,1969

2 Sheets-Sheet 2 INVENTOR WILLIAM F. MANNING United States Patent 3,471,174 BALLISTIC JACKET-PILE CONNECTION William F. Manning, Springdale, Conn., assignor to Mobil Oil Corporation, a corporation of New York Original application Sept. 23, 1965, Ser. No. 489,527, now Patent No. 3,352,119, dated Nov. 14, 1967. Divided and 1 this application Mar. 30, 1967, Ser. No. 651,072

Int. Cl. F16] 35/00, 55/00, 21/00 U.S. Cl. 28518 ABSTRACT OF THE DISCLOSURE The invention relates to a device for rigidly fixing a completely submerged anchoring pile within a tubular hollow mooring member, such as a structural support leg or jacket of an offshore drilling or production facility, through which it is driven. More particularly the invention relates to a ballistic device mounted on the outside of the tubular mooring member, to be anchored in the sea bottom, the ballistic device being remotely detonated so as to drive a spike or pin thereof through the outer member and an inner member or pile whereby the two members are held rigidly with respect to each other prior to grouting and during the setting period of the grout pumped into the annular space therebetween.

This application is a division of application Serial No. 489,527 filed Sept. 23, 1965, now Patent No. 3,352,- 119.

Present developments in the offshore oil and gas industry indicate that production efforts will be extended to underwater areas where permanent surface installations are neither as economically nor technologically feasible as they are in the Gulf of Mexico where most experience with offshore completions has previously been obtained. Even where the depth of thesea does not prohibit the use of surface structures, it is usually advisable to shelter as much of the equipment as possible beneath the surface to avoid the forces produced by hurricanes and other violent storms as well as the everyday effects of tides and, in the northern latitudes, ice formations. The term sea is used here to denote a body of water in which it is contemplated to use the invention, and it is meant to encompass any and all open ocean, coastal, or inland submerged land areas.

When mooring permanent facilities for offshore oil or gas production, beneath the surface of the sea, one of the problems that has been encountered is that of forming a good cement bond between the pile and the leg or jacket by which the structure is moored. In above-surface installations, where the pile is driven down through the mooring leg or jacket into the sea bottom, with the upper end of the pile still extending above the surface at the upper end of the jacket, the pile may be temporarily welded to the jacket above the surface to provide a rigid connection during the grouting operation so that the members will not move relative to each other until the grout sets. When the entire facility is considerably below the surface of the sea, such as when mooring a subsea production gathering satellite, or an underwater storage facility as shown in the Crawford et al. patent, No. 3,113,699, issued Dec. 10, 1963, welding cannot be relied on even when a diver can reach the upper end of the pile and the leg or jacket.

The present invention can also be used when driving a short pile down through a leg or jacket extending above the surface, into the botom, where the pile is not designed to extend all the way back to the surface. Such a structure is disclosed in the application Serial No. 266,734, new Patent No. 3,213,629, for Apparatus and Method 5 Claims I 3,471,174 Patented Oct. 7, 1969 for Installation of a Pile-Jacket Assembly in a Marine Bottom by William F. Manning. In this instance the object is to foreshorten the length of the pile so that the hammering energy needed to drive it through the leg or jacket will be less. The forces tending to compress or flex the pile during hammering are disclosed as generally proportional to the length of the pile and therefore shortening the pile will lessen the energy expended in driving it. The pile driving hammer, as shown in the above-discussed patent application, will be lowered down into a casing to impart blows to the pile until the pile is secured in the sea bottom with the upper end thereof far beneath the surface, although the top of the casing remains above the surface.

Accordingly, it is an object of this invention to provide a remotely controlled device for connecting concentric tubular members beneath the surface of a body of water.

It is another object of the invention to provide a ballistic device for rigidly connecting a pile to a hollow jacket or leg through which it is driven.

Other objects and advantages of this invention will become readily apparent from the following description when taken in conjunction with the accompanying drawings and the illustrated useful embodiments in accordance with this invention:

FIGURE 1 is an illustrative representation of a subsea gathering and storage system using the ballistic jacketpile connection of the invention;

FIGURE 2 is an elevational view of a jacket-pile showing the ballistic device of the present invention mounted on the jacket; and

FIGURE 3 is a fragmentary sectional view taken through lines 33 of FIGURE 2 illustrating the details of the ballistic device.

The ballistic device of the present invention is primarily designed to fix the relative positions of a completely submerged pair of telescoped elongated members, such as a hollow jacket or leg and a pile driven there through into the sea bottom. Due to the versatility of the device, the connection can be made at any point along the members rather than just at the upper ends as with the previous method, discussed above, where the upper ends of the members, above the surface, would be welded together. One or more of these ballistic devices is mounted on the outside of the hollow outer member, the leg or jacket, preferably over a hole drilled therein. Upon the detonation of a charge within the ballistic device, a spike or rod within the device is driven through the drilled hole in the wall of the jacket or leg and through the wall of the hollow pile therewithin.

The ballistic device, as designed, is a hollow cylinder having a slidable piston fitted therewithin. The cylinder is mounted on the outside of the leg or jacket with its axis substantially radially disposed with respect to the axis of the leg or jacket. An explosive charge is packed into the far end of the cylinder, adjacent the outer face of the piston, while a spike or rod is fitted on the inner face thereof. The spike may extend beyond the cylinder prior to detonation to permit the cylinder to be lined up with respect to a preformed hole in the leg or jacket before being fixed thereto. Upon detonation of the charge outward of the piston, the spike is driven inward, through the preformed hole in the leg or jacket and the wall of the enclosed pile to hold the two members together. Grout is then pumped into the annulus between the members where it later sets to hold the pile permanently within the jacket.

Depending on the stresses involved, more than one ballistic device may be attached to the outer face of a single leg or jacket. These devices can be in line along the axial length of the leg or jacket or equiangularly spaced in a single plane perpendicular to the axis thereof. As shown in the drawings, a plurality of devices are spaced around the leg or jacket and held against the wall thereof by an interconnecting circumferential spacer ring or brace. Only two ballistic devices are shown connected by a single brace; however, three or more could be fixed, equally spaced, by the same brace and even more than one layer of them could be used for a single connection.

Although the primary function of the ballistic device is to form a temporary connection, prior to grouting, under certain circumstances the ballistic connection could form the only means of attaching elements. The use of the device depends on the intended use and the loads imposed on the structure being fabricated or moored.

FIGURE 1 shows a subsea gathering and storage system anchored on the sea bottom far beneath the surface. A satellite is anchored on the bottom within a ring of submerged wellheads 12, capping directionally drilled Wells diverging outward beneath in the subaqueous earth. The satellite 10 is interconnected with each wellhead 12 by a flexible conduit 14 containing the necessary control and production lines. A further conduit 16, carrying air and electrical communication lines, connects the satellite 10 with a point above the surface of the water through a buoy 18 moored by a pair of guidelines 20. The satellite 10 is also connected, by shipping lines 22, to a bottomanchored storage tank 24. The storage tank 24 is interconnected with the surface by a single buoy mooring system 26 shown in more detail in the patent of Isaac Ault, No. 2,701,375, issued Feb. 8, 1955. A hollow conduit 28 and the buoy anchoring lines 30 extend from the storage tank 24 to the surface.

The satellite 10 and the storage tank 24 are both necessarily rigidly anchored into the sea bottom. Since it is desirable to have no rigid elements extending to the surface, to lessen navigational hazards, as well as to secure all of the permanent facilities in the less turbulent bottom waters, short jackets 32 are mounted vertically and equally spaced around a peripheral lip 34 on the lower end of the satellite 10 and the peripheral lip 36 on the lower end of the storage tank 34. Due to the size of the storage tank 24, the jackets 32 thereon may be of a larger diameter and cross braced by diagonal struts 38 between the jacket 32 and the lip 36 and horizontal struts 40 between the jackets 32 and the walls of the storage tank 24 itself.

As shown in FIGURE 2, each of the jackets 32 illustrated has a cylindrical body 42 and a conical upper guiding section 44. Annular seals 46, fixed in the upper and lower ends of the body 42 of the jacket 32, are designed to coact with the outer face of a tubular pile 48 driven into the subaqueous earth through the jackets 32. A grout port 50 traverses the jacket wall between the seals 46 and has a grout line 52 connected thereto for injecting the cementitious material into the annular space 53 between the hollow members directly from a ship or station (not shown) on the surface or from the interior of the satellite 10. Another port (not shown) may be positioned in the wall of the jacket body 42 between the seals 46 for removing the water from the sealed annular space 53.

A plurality of ballistic units 54 are tightly fixed to the outer surface of the jacket 32 by a circumferential spacer ring 56 holding the group of units in place. Each of the units 54 is aligned by a spike 58 extending therefrom (FIGURES 2 and 3) and a short distance into the annular space 53 through preformed holes 60 (FIGURE 3) in the jacket wall.

As shown in FIGURE 3, each of the units 54 is a closed cylinder with the inner end 62 slightly concave to match the curvature of the jacket wall. A piston head 64 is slidable in the axial direction in a central coaxial chamber '66 therewithin, the axial spike 58 being fixed to the inner face of the piston head 64 and extending through a coaxial hole 67 in the inner concave end 62 making a watertight seal with an O-ring 68 in the wall thereof. An explosive mixture 69, which can be electrically detonated, either directly or indirectly, is packed into the area within the chamber 66 beyond the outer face of the piston head 64. The piston head 64 is held from movinginward prior to detonation by a frangible ring 70 set in a groove 72 just ahead of the inner face of the piston head. Threaded into the outer end of the chamber, beyond the piston head 64, is an electrical connector and detonator 74 connected by electrical wires 76 outside the unit 54 with a remote detonator control (not shown) on a surface ship or station or in the satellite 10. A relief port 78, formed in the inner end of the chamber 66 to allow any included gas to escape in advance of the piston head 64 during detonation, is closed by a frangible plug 80 strong enough to keep the inner end of the chamber watertight but not strong enough to hold against the explosive pressures.

For ease of assembly, the piston head 64 is set into the chamber 66, after the locating of the frangible ring 70, from the outer end. A threaded closure plate 82 is then screwed into the outer end of the chamber 66, the explosive agent being added through a port 83- in the closure plate 82. A plug 84 is adapted to be threaded into the port 82 to complete the watertight integrity of the chamber 66.

Prior to lowering the satellite 10 into the water, the jackets are drilled with the spike holes 60', as many as the number of connections needed for the satellite. A ballistic device 54 is placed over each hole 60 with the spike 58 fitting into the hole. The ring 56 is set overeach set of two ballistic units 54 and is welded thereto and 'to the jacket 32. After so modifying each jacket 32 the satellite 10 is lowered to the bottom and piles 48, guided into each of the jackets 32, are driven into the bottom by any suitable method. The ballistic units 54 are then detonated to connect rigidly the packet-piles after the piles have been driven in as far as possible. Grout is injected into the annular space 53 and after this cementitious material has set and hardened, the useful function of the temporary ballistic connection is at an end, the satellite being securely anchored in the bottom.

The storage facility 24 is similarly anchored into the bottom. Due to its larger size and greater frontal area for forces of the sea to act upon, the jackets 32 and piles 48 would probably be scaled up in size and more ballistic units 54 would be used on each packet-pile.

Although the present invention has been described in connection with details of the specific embodiments thereof, it is to be understood that such details are not intended to limit the scope of the invention. The terms and expressions employed are used in a descriptive and not a limiting sense and there is no intention of excluding such equivalents, in the invention described, as follows in the scope of the claims. Now having described the apparatus herein disclosed, reference should be had to the claims which follow.

What is claimed is:

1. A ballistic device for connecting submerged coaxial members comprising: at least one hollow closed cylinder, means adapted for fixing said cylinder to the outer surface of the wall of the outer of the coaxial members with the axis of said cylinder substantially radially oriented with respect to the longitudinal axis of the outer coaxial member, an axial spike slidably carried within said cylinder and adapted to be coaxial with a preformed radial hole through the wall of the outer coaxial member when said cylinder is fixed to the outer surface of the wall of the outer member, a slidable piston means within said cylinder adapted to be driven toward the coaxial members, said spike being operatively connected to the forward face of said piston means, an explosive mixture within said cylinder adapted to act against the rearward face of said piston means, and means extending through said closed cylinder for detonating said explosive mixture to drive said spike through the preformed hole in the outer member and into 5 the wall of the inner member when said cylinder is in place on the outer member.

2. The ballistic device of claim 1 wherein there are a plurality of cylinders adapted to be arranged around the outer surface of the outer coaxial member and adapted to be fixed thereto by a circumferential spacer ring, said slidable spike in each cylinder adapted to be coaxial with one of a plurality of preformed holes through the wall of the outer member when said cylinders are in place whereby multiple connections between the coaxial members can be produced.

3. The ballistic device of claim 1 wherein there is a port through a wall of said cylinder connecting with the piston chamber therewithin forward of the position of said piston prior to detonation, frangible means for sealing said port prior to detonation whereby the air in said chamber forward of said piston can be expelled during detonation.

4. The ballistic device of claim 1 wherein said slidable spike extends out of an end of said cylinder and at least partially through said coaxial preformed hole prior to detonation when said device is in place.

5. The ballistic device of claim 1 wherein said detonating means is a means for passing an electric current 3,334,924 8/1967 Todd 2853 X THERON E. CONDON, Primary Examiner 15 NEIL ABRAMS, Assistant Examiner US. Cl. X.R.