Kuwaiti Pat 39/94

Priority Documents British Patent Office:
9105690.3 dated 18.3.1991
9109548.9 dated 2.5.1991<

Because the damage was in the middle of the desert the patents specify control of fires by firstly, a break in the column of liquid technique and the use of inert gas or simply by dropping the pipe onto the ground to prevent air entering the pipe. The extinguishing of the fires was not considered a problem. With this specification it was intended to allow the escaping oil to burn at the top of the tube and even add air or oxygen to the burning process to increase the efficiency of the oxidation of burning material so that less pollutants remained to be deposited on the ground. It was proposed to allow the fires to continue burning whilst the well head was serviced. When the fire need to be put out, the preferred method was to simply and promptly move the entire containment assembly out of the way, upwind. The break in the flow of escaping material removed the source of heat at the burning end so that fresh escaping material could not ignite. The valve assembly was then bolted onto the repaired riser pipe and the oil turned off.

The other method originally considered was the use of liquid nitrogen pumped into the lumen of the displacement tube. A fire is a well understood chemical reaction between oxygen and the combustible material. Remove any of the principal factors involved in a fire and the fire cannot occur. Pumping of nitrogen gas into the lumen of the tube, displaced the oxygen from the environment of the escaping oil and no fire could occur.

The above procedures were specified because no water was available to hand and the prospect of pumping millions of gallons of water from a far distance, was considered impractical.

The above patents continue to be useful for all positive pressure applications particularly for well pressures exceeding 5000lbs/sq inch.

The other way of containing the escaping pressurized materials that was presented to the Kuwaiti authorities was the Counter Pressure Plug System. The Patents relating to this technology:

Patents in Kuwait:

Kuwaiti Pat No 40/94

Priority Documents British Patent Office:
9106872.6 dated 2.4.1991
9107521.8 dated 10.4.1991
9108270.1 dated 18.4.1991
9110973.6 dated 21.5.1991

In this, the preferred method of staunching the flow of escaping material from the damaged well heads, a heavy metal plug was lowered into the opening of the damaged pipe. A member of designs were presented coping with most of the possible situations that were envisaged. The counter pressure plugs were designed to staunch the flow by exerting downward pressure that was greater than the pressure of the escaping material. Escaping material was staunched in the same way that a cork blocks the opening of a champagne bottle. The total weight of the plug exceeded the total pressure of the damaged oil well. Provision was made to vary the total weight of the plugs, by adding or removing the 500kg steel plates secured to the neck of the plug design. A self locating attachment (18) was designed to respond to the flowing mass of escaping oil that directed the point of the plug into the region of maximum flow and hence into the largest opening in the damaged pipe. In this way the plug would locate the opening in response to the flowing mass and could be used in situations where visibility was obscured or in situations where the damaged pipe was below the surface in a pool of oil.

Destroyed installations were classified into the type of damage resulting and plugs designed to cope with the specific problem:

1. Counter pressure plug for regular riser pipe openings.
2. Counter pressure plugs for imploded or irregular openings. The universal plug.
3. Counter pressure plugs for longitudinal fractures of the riser pipes, i.e. along the length of the pipe.

To prevent the escape of oil once the plug was withdrawn so that the valve assembly could be bolted to the repaired flange, a frozen plug technique was also patented. In this technique a deep hole was dug adjacent to the riser pipe and a thermally insulating jacket was positioned around the riser pipe. Liquid nitrogen was pumped into this jacket surrounding the riser pipe so that the oil in the pipe forms a solid frozen oil plug. The counter pressure metal plug was then removed and the valve assembly bolted on to the repaired riser pipe.
No oil escaped because the frozen oil plug blocking the riser pipe. The use of this patent provided a means wherein the engineers could work in safety and free from escaping oil whist the valve system was placed in position. The installation was then left to thaw out and the oil could flow again.

The use of this technology could have contained the carnage in the Kuwaiti oil fields in a matter of weeks. It is reported that the Kuwaiti people were losing 60 million dollars per day in lost revenues because of the escaping oil. The containment of the damage took some eight months to complete.

Well over half of all the damaged installations in the Kuwaiti oil fields, were contained using the displacement tube patented technology. The Kuwaiti People were said to have paid in excess of 2 Billion pounds (2000 million pounds), for the repair works.

Specific modifications to the technology can be tailored to any given oil extracting problem. This technology can be bought outright or licensed to oil extracting companies as a first means of coping with escaping oil from pressurized installations.

The above technology remains the best way, to contain damaged pressurized installations.

Innovative uses of removing gases from a contained space, open up the possibility of using nitrogen gas to contain fires in high rise buildings, house fires and any other situation where the fire is well contained. Any house fire for example would benefit from the technology because a house is compartmentalized and each room is a container into which enough oxygen has to be delivered for a fire to burn. By pumping into any such contained space, nitrogen gas, the essential element for a fire, is removed and no oxidative process can occur. The pumping of the nitrogen gas is continued until the temperature in any treated space falls below the spontaneous combustion temperature after which time, the nitrogen gas can be allowed to ventilate out of the treated space.

This technology is ideal for containing fires in inaccessible areas because the quantity of nitrogen required to contain the problem can be manhandled into place. This technology should be the firefighting technique of choice for high rise buildings, allowing fire fighting teams to drill small holes via which to pump nitrogen gas into any given space. We are keen to work with firefighting departments around the world to try and modify the use of this technique to specific problems.