RISER TO THE WELLHEAD

TECHNICAL FIELD

The present invention relates to the field of petroleum engineering, in particular, to the cmde oil, natural gas, and natural resource platform devices.

BACKGROUND OF THE INVENTION

In the petroleum industry, the wellhead riser is one of the most important drilling equipment for the connection between the wellhead on the wellhead production deck, and the blowout preventer (BOP) on the upper deck vertically. It is important to install the wellhead riser during and after the drilling in order to transfer fluids formed during drilling. Moreover, the wellhead riser also functions as a pressure protector from the well when the well pressure needs to be controlled. Therefore, the connection joints of the wellhead riser need to be tested for their pressure resistances after being installed before being used in the actual drilling operation.

Normally, the testing of the pressure resistance of fluid inside the wellhead to the wellhead riser and the petroleum blowout preventer device can be completed by disposing of the test plug tool into the wellhead after all equipment were installed and connected to test the field connection efficacy before the actual drilling operation. This test can take a long time because of the translocation and installation of the testing devices.

Moreover, the wellhead risers commonly used in the drilling industry are very heavy and need to be tested for pressure resistance both inside the well and pressure against the petroleum blowout preventer device. The translocation of the heavy wellhead riser from one well to another well by rig system takes a long time. Moreover, the wellhead riser is generally designed to tolerate pressure of about 10,000 pounds per square inch (psi). It is found that the working pressure in some areas such as the Gulf of Martaban is only 5,000 psi. Therefore, the wellhead riser is generally designed to tolerate pressure at about 10,000 psi, which means the wellhead riser is very thick and is unnecessarily heavy. This increases the translocation time.

This invention aims to develop a wellhead riser that can be connected into the device for testing and direct monitoring the connection efficacy of said wellhead riser to the wellhead in order to develop the performance efficacy, which is one important factor of the profitable success in the natural gas and oil platform industry competition.

SUMMARY OF THE INVENTION

This invention aims to provide a wellhead riser capable of testing and direct monitoring the connection efficacy of the wellhead riser to the wellhead from the use of the external connecting tool connected to the external port, wherein the wellhead riser (100) comprising:

the hollow cylindrical body (110) connecting between the blowout preventer connector (BOP connector) (120) and the wellhead connector (130) of said hollow cylindrical body, where the gasket groove (131) is disposed in the wellhead connector (130); the ring gasket (200) having the gasket passage way (210) disposed in the gasket groove (131); and

c. the external port (300) disposed in the wellhead connector (130);

characterized in that the wellhead connector (130) comprising at least one annular bore (132), wherein one side of the annular bore (132) connects between the external port (300) and the gasket groove (131) to allow the fluid inside the hollow cylindrical body (110) flowing through the gasket passage way (210) to the external port (300) or vice versa , in order to test whether the connection of said wellhead riser (100) to the wellhead (500) is effective.

The other objective of this invention is to provide a light weight wellhead riser that can tolerate the pressure of the wellhead riser.

Other objectives and characteristics of this invention will be clearer when considered together with the appended drawings and the detailed description of the best mode of the invention which will be described in the following. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows the wellhead riser connected to the lower wellhead and connected to the upper petroleum blowout preventer device.

Figure 2 shows the wellhead riser according to this invention comprising the hollow cylindrical body, connecting the petroleum blowout preventer, and the wellhead connector.

Figure 3 shows the wellhead riser according to this invention that shows the annular bore, the gasket groove, and the external port. Figure 4 shows the laboratory pressure resistance testing model of the connecting part having BX gasket with the gasket passage way comprised in the testing kit.

Figure 5a shows the laboratory pressure resistance testing model of the connecting part from internal pressure in the testing kit.

Figure 5b shows the laboratory pressure resistance testing model of the connecting part from external pressure in the testing kit.

DETAILED DESCRIPTION OF THE INVENTION

The present invention aims to provide a wellhead riser capable of testing and direct monitoring the connection efficacy of the wellhead riser to the wellhead, from the use of the external connecting tool connected to the external port as detailed in the description and drawings below.

Any aspect being described here is meant to include the application of the other aspects of this invention, unless stated otherwise.

Definition

Technical terms or scientific terms used here have definitions as used by a person skilled in the art unless stated otherwise.

Any tools, equipment, methods, or chemicals named here mean tools, equipment, methods, or chemicals being used commonly by a person skilled in the art unless stated otherwise, that they are tools, equipment, methods, or chemicals specific only in this invention.

Use of singular noun or singular pronoun with “comprising” in claims or specification means“one” and including“one or more”,“at least one”, and“one or more than one” too.

Throughout this application, term“about” means any number that appeared or showed here that could be varied or deviated from any error of equipment, method, or personal using said equipment or method.

“Wellhead” includes the drilling wellhead for, including by not limited to, crude oil, natural gas, subsea resources, or the like thereof.

“External connecting tool” refers to the device that can be assembled to the external port in order to test the connection efficacy of the connection device and/or the fluid property inside the pipe, including but not limited to, pressure testing device, pressure gauge, vacuum gauge, gate valve, needle valve, check valve, pump, grease plug, and bleeder plug, or others having similar utilities.

“Place”,“put on”,“insert”,“connect”,“link to”,“connect to”,“dispose”,“placing”, “putting on”,“inserting”,“connecting”,“connecting to”, or other similar words, when being used with the external connecting tool according to this invention means the use of said device by placing, putting on, inserting, connecting, connecting to the external port of the wellhead riser in order to contact said external connecting tool to the fluid inside the pipe that may flow through gasket passage way to the external port or vice versa , to determine that whether or not the connection of said wellhead riser (100) to the wellhead (500) is effective. It should be noted that the shape of said external connecting tool is not necessary to be as same as the external port or perfectly fitted, fixed, attached, or locked into the external port.

In one embodiment, the wellhead riser (100) comprising:

the hollow cylindrical body (110) connecting between the blowout preventer connector (BOP connector) (120) and the wellhead connector (130) of said hollow cylindrical body, where the gasket groove (131) is disposed in the wellhead connector (130); the ring gasket (200) having the gasket passage way (210) disposed in the gasket groove (131); and

the external port (300) disposed in the wellhead connector (130);

characterized in that the wellhead connector (130) comprising at least one annular bore (132), wherein one side of the annular bore (132) connects between the external port (300) and the gasket groove (131) to allow the fluid inside the hollow cylindrical body (110) flowing through the gasket passage way (210) to the external port (300) or vice versa, in order to test whether the connection of said wellhead riser (100) to the wellhead (500) is effective.

In another embodiment, the petroleum blowout protection connector (120) further comprising the gasket groove, gasket passage way disposed in the gasket groove, external port, and annular bore as same as in the wellhead connector (130).

In another embodiment, the annular bore (132) has a diameter in a range of 0.15 to 0.25 inches. In another embodiment, the annular bore (132) has a shape selected from hemisphere, dome, cylinder, or cone. In case the wellhead connector (130) comprising more than one annular bores (132), the shapes of the annular bore (132) are not limited to be the same.

In another embodiment, the wellhead riser further comprising the external connecting tool (310) disposed in the external port (300) for monitoring the connection efficiency of said wellhead riser (100) to the wellhead (500).

In another embodiment, the external connecting tool (310) is selected from pressure testing device, pressure gauge, vacuum gauge, gate valve, needle valve, check valve, pump, grease plug, and bleeder plug.

In preferable embodiment, the external connecting tool (310) is the pressure testing device.

In another embodiment, the external port (300) has a diameter in a range of 0.125 to 2.0 inches.

In preferable embodiment, the external port (300) has a diameter in a range of 0.375 to 0.75 inches.

In another embodiment, the hollow cylindrical body (1 10) has an external diameter in a range of 15 to 20 inches.

In another embodiment, the wellhead riser further comprising the connector bolt (140) for tightened fixing of the wellhead riser to the wellhead.

Hereafter, invention embodiments are shown without any purpose to limit any scope of the invention.

Figure 1 shows external configuration of the wellhead riser (100) which is the cylindrical pipe and comprising two connecting parts. The lower connecting part is fixed into the wellhead (500) fixed into the casing protruded from the sea floor (600). The upper connecting part is fixed into the petroleum blowout preventer device (400). In both connecting parts, the wellhead connector (130) is fixed into the wellhead (500), and the blowout preventer connector (120) is fixed into the petroleum blowout preventer device (400) with the bolts as shown in the drawing. The crude oil or natural gas obtained from the wellhead (500) will be conveyed via the wellhead riser (100) to the petroleum blowout preventer device (400) up to the topside offshore platform (not shown in the drawing).

Figure 2 shows internal configuration of the wellhead riser (100) comprising the hollow cylindrical body (110), the blowout preventer connector (120), and the wellhead connector (130). The hollow cylindrical body (1 10) has linear cylinder shape, and the connecting part is the flange on both ends.

Figure 3 shows the wellhead connector (130) showing the annular bore (132), the gasket groove (131), and the external port (300) disposed in the wellhead connector (130). The wellhead connector according to this invention comprises the gasket groove (131) connected to the annular bore (132) and the external port (300). However, there is no limitation in the arrangement of the gasket passage way (210) regardless of whether it is located in the same array to the annular bore (132). Moreover, the wellhead riser may comprise the connector bolt (140) for tightened fixing of the wellhead riser to the wellhead.

Moreover, the blowout preventer connector (120) may comprise the gasket groove (131), the ring gasket (200) having the gasket passage way (210) disposed in the gasket groove, the external port (300), and the annular bore (132) as same as in the wellhead connector (130).

In case of complete or effective connection between the wellhead riser and the wellhead, the fluid inside the pipe will not be able to flow through the gasket passage way (210) and the annular bore (132) to the external port (300). On the other hand, the external fluid will not be able to flow into the pipe. This makes the complete conveying through the wellhead riser to the wellhead. In case of incomplete connection or if the internal pressure is higher than the value used to be tested which causes the incomplete connection, or ineffective connection, the connecting parts will become separated. Therefore, the fluid inside the pipe can flow through the gasket passage way (210) and the annular bore (132) into the external port (300). On the other hand, in case of incomplete connection, the external fluid may flow through the external port (300), through the annular bore (132) and the gasket passage way (210) into the inside of the pipe.

From the above configuration, the device according to this invention can be applied in the testing of the connecting efficacy of the wellhead riser (100) by connecting the external connecting tool (3 10) to the external port (300) according to the following description of the testing method of the connection of the wellhead riser. The external connecting tool (310), for example the pressure testing device, is disposed into the external port (300) which is capable of providing the pressure and capable to measure the pressing force. Therefore, it can be used to test the pressure against the connecting parts. Alternatively, the pressure gauge can be disposed in to the external port (300) in order to measure the internal pressure of the pipe that leaks from the connecting part. Moreover, in the same aspect as described above, the external connecting tool (310) can be further selected from, but not limited to the vacuum gauge, gate valve, needle valve, check valve, pump, grease plug, or bleeder plug for different purposes. However, in case there is no operation on the annular bore (132), the screw can be added into the external port (300) for stoppage of internal pressure of the pipe.

As an example and for better understanding of the invention, this invention tested the pressure resistance of the gasket and the gasket groove using the laboratory pressure resistance testing device of the connecting part prior to field use. The API BX pressure- energized ring gasket was used in the test. The BX-160 was used to test for the maximum pressure of 5,000 psi. The BX-159 was used to test for the maximum pressure of 10,000 psi. The pressure resistance testing device of the connecting part was made as shown in figure 4. Therefore, the 5,000 psi pressure was an averaged pressure for the field use. The 10,000 psi pressure was the pressure according to the laboratory test regulation.

Figure 4 shows the overview of the laboratory pressure resistant testing of the BX gasket with the passage way for the testing of pressure resistance of the connecting parts. The gasket (200) having the gasket passage way (210) disposed in the gasket groove (131) (shown in the expanded circle in figure 4) of 4 external test ports comprising the external test port a (350), external test port b (360), external test port c (370), and external test port d (380). In this testing, the external test port b (360) and external test port d (380) had not been used and were closed. The testing steps were the following.

1. Testing of the internal pressure of the pipe to the connection efficacy

The pressure resistance of the connecting part from the pressure inside the pipe was tested at the pressure levels of 5,000, 7,500, and 10,000 psi. The external test port c (370) was connected to the pressure testing tool which was the external connecting tool in order to give hydrostatic pressure which was on the top of the testing device. The pressure gauge was connected to another test port which was the external test port a (350) as shown in figure 5 a. When there was excess water pressure from inside of the pipe over the limitation of the connection efficacy, the connection was incomplete. When the connection was incomplete, the water inside the pipe would flow through the external test port c (370) via the gasket passage way (210) and the annular bore (132) to the external test port a (350). Therefore, the pressure gauge connected to said external port could record the pressure when the pressure at the external test port a (350) was found, and increased the hydrostatic pressure in terminate the test.

2. Testing of the external pressure of the pipe to the connection efficacy

The pressure resistance of the connecting part from the pressure outside the pipe was tested at the pressure levels of 5,000, 7,500, and 10,000 psi. The external test port a (350) was connected to pressure testing tool which was the external connecting tool in order to give hydrostatic pressure which was on the top of the testing device as shown in figure 5b. When there was excess water pressure from outside of the pipe over the limitation of the connection efficacy, the connection was incomplete. When the connection was incomplete, the water outside the pipe would flow through the external test port a (350) via the annular bore (132) and the gasket passage way (210) to the external test port c (370). Water could be seen flowing out of the external test port c (370). The result obtained from the pressure testing device indicated the pressure from the external pressure caused the inefficient connection.

From the tests using BX- 159 and BX- 160 gaskets in the testing of pressure resistance of the connecting parts via the external test port using laboratory external test device at the pressure levels of 5,000, 7,500, and 10,000 psi, it was found that the pressure resistance could be tested in the fieldwork at about 10,000 and about 5,000 psi. The results showed that the wellhead riser according to this invention could be practically used. It could resist pressure higher than the pressure which really occurs in the wellhead and/or the pressure which really occurs against the petroleum blowout preventer device. The wellhead riser according to this invention has a lighter weight than the conventional one, which can reduce the time and format of the hoist.

As shown above, the testing of pressure resistance according to this invention can also be performed in the fieldwork by applying the pressure from the external connecting tool (310) to the testing device in which the pressure can be delivered from the external port (300) via the annular bore (132) to the gasket passage way (210) by stepwise increase of the pressure to the level needed to be tested. The advantage of this method is that the connecting efficacy of the wellhead riser according to this invention can be tested regardless of whether it can resist the pressure in the practical fieldwork.

The principle of the devices and methods described in this invention is aimed to cover the embodiments that have not been practiced, modified, or changed in any parameter that are significantly different from this invention which can obtain the similar properties, utilities, and results as this invention according to the persons skilled in the common art without being described particularly in the appended claims. Therefore, the replaceable or similar aspects to the aspects of the present invention, including any little modifications or changes that can be clearly seen by persons skilled in this art should be considered as included in the scopes, spirits, and concepts of the invention as shown in the appended claims.

BEST MODE OR PREFERRED EMBODIMENT OF THE INVENTION

Best mode or preferred embodiment of the invention is as provided in the description of the invention.