Month: January 2011

GN solids control designed and manufactured slurry separation system for TBM project. GN250, GN400, GN600 is special for TBM project in Hongkong.

What is TBM?

A tunnel boring machine (TBM) also known as a “mole”, is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They can bore through hard rock, sand, and almost anything in between. Tunnel diameters can range from a metre (done with micro-TBMs) to almost 16 metres to date. Tunnels of less than a metre or so in diameter are typically done using trenchless construction methods or horizontal directional drilling rather than TBMs.

Function of TBM

Tunnel boring machines are used as an alternative to drilling and blasting (D&B) methods in rock and conventional ‘hand mining’ in soil. TBMs have the advantages of limiting the disturbance to the surrounding ground and producing a smooth tunnel wall. This significantly reduces the cost of lining the tunnel, and makes them suitable to use in heavily urbanized areas. The major disadvantage is the upfront cost. TBMs are expensive to construct, and can be difficult to transport. However, as modern tunnels become longer, the cost of tunnel boring machines versus drill and blast is actually less—this is because tunnelling with TBMs is much more efficient and results in a shorter project.

GN400 slurry separation system is composed of the following items:

1 GNZS83-3 shale shaker 2sets , with 2.7m3 pyramid screen area and max 7.0G vibrating strength

The shaker screen is not same as common oil drilling shaker screen, it is a kind of slit type shaker screen, material is stainless steel wire. It can process large solids such as rocks, the function is same as scalper. But if the solids in the mud is not so large, you can change a small mesh screen so that the treatment effect could be better, so it is much flexible than scalper.  

2 GNZJ83-3 desander 1set, use 3 pcs 12” PU hydrocyclones with underflow shaker GNZS83-3

3 GNZJ83-3 desilter 1 set, use 18pcs 5” PU hydrocyclones with underflow shaker GNZS83-3

 5”  Hydrocyclones can process larger capacity than conventional 4” cone, and it is not easy to jam the inlet of desilter. The GNZJ83-3 desilter is designed of round arrangement, the round arrangement is with compact structure and better performance than horizontal line.

Continue reading “Slurry separation system for TBM”

As refer to mud gas separator or poor boy degasser, you may heard of “Flare stack”.

A flare stack (alternatively known as gas flare ) is a vertical vent pipe used in oil and gas drilling sites. The pipe diameter of flare stack is usually 8” for GN ZYQ series poor boy degasser.

The function of flare stacks

They are used to eliminate waste gas invaded in the drilling mud, otherwise it will lead to “blowout”, “kick”. They also act as safety systems for non-waste gas and is released via pressure relief valve when needed to ease the strain on equipment. They protect gas processing equipments from being over pressured. Also in case of an emergency situation, the flare system helps burn out the total reserve gas.

How flare stacks work

Whenever the poor boy degasser are over-pressured, the pressure relief valves automatically releases gases which are routed through large piping runs called flare headers to the flare stacks. The released gases are burned as they exit the flare stacks. The size and brightness of the resulting flame depends upon the flammable material’s flow rate in terms of joules per hour.

In order to keep the flare system functional, a small amount of gas is continuously burned, like a pilot light, so that the system is always ready for its primary purpose as an over-pressure safety system. The continuous gas source also helps diluted mixtures achieve complete combustion. Enclosed ground flares are engineered to eliminate smoke, and contain the flame within the stack.

Continue reading “Flare stack/gas flare”

The mud gas separator is used in a ‘kick’ situation to separate large volumes of free gas invaded in the drilling fluid.

 Function of Mud gas separator

 Mud gas separator also called poor boy degasser, Gus buster, which is designed to provide effective separation of the drilling mud and invaded gas from the well by venting the gas and returning the mud to the mud pits. Small amounts of entrained gas can then be handles by a

vacuum-type degasser located in the mud pits. The mud/gas separator controls gas cutting during kick situations, during drilling with significant drilled gas in the mud returns, or when trip gas is circulated up.

 Mud leg height is an important parameter for the mud gas separator, you need to clear it during evaluation.

 What is Mud leg?

The mud leg in the separator is controlled by adjusting the fluid level in the mud tank or by moving the separat6or up or down within the tank. Mud tank height can restrict the maximum mud leg obtainable for open-bottom mud gas separator.

 Mud leg is an important part for mud gas separator, it is also called Fluid level. Fluids level is maintained in a float mud gas separator by a float/valve configuration. The float opens and closed a valve on the mud return line to maintain the mud leg level. Valves can be operated by manual linkage system connected from the float to the valve, or the valve can be air-operated with the rig air. Mud leg height can be controlled by adjusting the float assembly.

 There are some inherent problems in the use of float-type mud gas separators. The manual linkage separator has experienced problems with linkage failure resulting in improper opening or closing of the mud return line valve. Air-operated valves fail to function if rig air is lost, resulting in no control of fluid level within the separator. Mud-return-line valves are prone to plug with solids, preventing mud flow back to the mud pits.

 Gas Flow calculation is another important issue to evaluate the mud gas separator.  

Usually we need to calculate the following items.

Continue reading “How to evaluate a Mud gas separator”

GN produce centrifugal pump for VACUFLO vacuum degasser, usually it is installed on the skid of the mud tank,together with the feeding pump of desander&desilter. The flow rate various from 20m3/h ~400m3/h.

Firstly, we should introduceVACUFLO vacuum degasser briefly.

 Function of vacuum degasserAn efficient degasser is essential to safe and productive drilling operations. Gas present in the well bore can reduce the hydrostatic head in the well bore – with the potential for even greater gas influx and possible blow-out.

How do vacuum degasser work?

Vacuum degassers work by creating lower pressure inside a vessel so air or other gaseous impurities can be removed from a substance, such as water or even molten steel. The air is siphoned from the vessel after pressure is lowered enough to force the gas from the substance.

Features of Derrick VACUFLO vacuum degasser

Derrick’s Design

More Leaf Surface Area

Corrugated Fiberglass Leaves

Gas Extraction

Large Access Door

Compared with Derrick VACUFLO vacuum degasser, GN vacuum degasser has the following features.

1 Smaller area required

Because of different design, GN Vacuum dgasser do not a feeding pump, it is a self priming one, so you save a lot of area to install the feeding pump of vacuum degasser.GN vacuum degasser have a compact structure which can be installed on the tank easily.

Continue reading “Centrifugal pump for VACUFLO vacuum degasser”

Hole Openers are used for expanding the drilled hole，it is a kind of drilling rig tools. There are many good suppliers and manufacturer of hole opener in China, with  good quality and competitive price. Some of the manufacturer produced hole opener according to API standard.

 Function of Hole opener

 1. When drilling of the big hole is not possible because of the rig capacity.

2. When a satisfied penetration rate is not obtained in case of the big hole drilling, it is used after drilling with smaller bit.

3. When the hole direction most be controlled.

 Cutters of Hole opener

Several types of the cutter are

 made available for various formations to be drilled, such as soft, medium and medium hard formations. Type SM for soft to medium formation,type MH for medium to hard formation and type XH for hard formation. For soft to medium and abrasive hard formations, the cutters with tungsten carbide tips are also available.

 Fixed Diameter Hole Opener

 Fixed Diameter Hole Opener is used to enlarge a hole or connected with a bit on front end to drill pilot hole and enlarge hole. Fixed Diameter Hole Opener is a general hole enlarging tool and is designed for enlarging holes onshore and offshore in oilfield during drilling. It is made of tough heat treated alloy steel for maximum strength. Cutter arms, equipped with removable cutter, are hardfaced and welded on body. The hole openers have three or six jet tubes with replaceable nozzles,so that jet streams quickly clean the enlarged hole.

 How to inquiry or order the hole opener in China?

You need to advice the following information.

1 Hole size

2 Pilot hole size

3 Top and bottom connections

4 Fishing neck and bottom neck length and OD.

5 Types of cutters (SM, MH, XH)

Hole opener manufacturer in China

1 Lilin Group, loaded in Tianjin city.

LILIN is the largest manufacturer of downhole drilling motor in Asia area. also famous manufacturer of drill bits in china. The company most significant value is our leading edge technolog ies and engineers that continually innovate and create update product to apply our technology to drilling situations.

2 Kingdream Public Limited Company located in Wuhan city

To know more about hole opener manufacturer in China or other drilling rig tools manufactures, pls contact GN solids control.