Special techniques of online leak sealing and online leak repair
 

1.Introduction of online leak sealing and online leak repair:

In the case of leakage of oil, gas and water in the pressure pipe network, this technology is aimed at the leakage of various forms under the condition of no stopping production, without fire or safety, so that the leakage loss is reduced to a minimum and the accident can be avoided.

Our company has been engaged in the online leak repair technology since 2003. This online leak repair technology includes a set of series of products or series of products, which constitute a complete set of three-dimensional technology to deal with oil, gas, water pressure pipeline, ground equipment and other leakage. There are thirteen items of patent products. At present, this online leak repair technology has been successfully applied in Zhongyuan Oilfield, Shengli Oilfield, Henan oilfield, Daqing oil field, Jilin oil field, Dagang oil field and CNOOC. In the past ten years, good results have been received in safety production and economic benefits.

The main innovation of online leak repair technology is to seal the leakage with pressure without stopping production, fire or safety, including plugging welding technology, steel belt tightening technology, rapid binding technology, low pressure adhesive technology, clamping injection of leak sealing compound technology and so on. And each technology has formulated detailed operating procedures, standardizes the plug - in products, and overcomes the shortcomings of the past leak - stoppage products with strong random, long cycle and slow operation in the field.

For example,the steel belt tension technology has realized the semi mechanization of the operation; the fast binding technology will stop the leakage.

The fixing and sealing parts of the product are integrated into one, and the operation is simple; the low pressure adhesive technology applies the patented technology of the wall hanging type plugging device, and the injection type sealing technology has developed the sealing injecting agent to deal with the micro and the filling and the double-layer fixture for protecting the leakage body.

Technology maturity and reliability: after ten years of the use and training of a large number of production units, the technology has become mature, its safety, reliability, rapid, easy to work and other characteristics have been recognized, in the petroleum, CNOOC, Sinopec and other enterprises to get through. This project has won the prize for scientific and technological achievements in safety production. The qualified rate of this product is higher than 99%, and the safety and reliability of this product can reach 100% in actual use.

 

2.Introduction of eight techniques of online leak sealing and repair:

2.1.Steel belt tightening technology

The steel belt tightening technology is a specialized technology for the leakage of pressure pipe leakage through the professional steel belt tightening tool and the related steel strip to tighten the leak stoppage. The technology of steel belt tensioning technology needs no prefabrication, which overcomes the defect of long prefabrication time of clamp. It has strong strain ability for the leakage field, and can be widely used in straight pipe, tube, three - way pipe, flange weld, elbow, body and so on under pressure of 1.6MPa. For the leakage of pressure level below 1.6MPa, traditional hoop stop leakage method is adopted. This method has long prefabrication time and poor strain capacity on the spot. It is difficult to apply to the tee, flange root, straight pipe uneven or narrow position. The steel belt tension technology overcomes these defects better.

2.2.Rapid binding technology

Fast bundling technology is a kind of leak stopping technology which can stop the leak by bundling the leak part quickly. All plugging products can be divided into two parts from the structure, namely the fixing part and the sealing part. The two part can form a new sealing system at the leakage place, resulting in plugging effect. The fixing and sealing parts of most of the plugging products are independent of each other, and the bandage is a sealing product with the fixation part and the sealing part. In the binding, with the thickening of the bandage, the pressure can be produced continuously, thus the purpose of rapid strapping and plugging is achieved.

2.3.Low pressure adhesive technology

Low pressure adhesive technology is chemical bonding technology, it is a kind of leakage control technology through a kind of diversion device, using professional adhesive to leak leakage control of the leakage body. It is usually constructed at room temperature without special equipment and energy, so it is also called cold welding technology.

The low pressure adhesive technology used to control the leakage of oil and gas pipelines is to use mature adhesives to plug the leakage. The existing adhesives are not easy to be bonded directly with pressure. The difficult point in the field application is to develop a kind of diversion device to realize the pressure adhesive. The patent product guide cap is such a diversion device. To ensure the success rate of low pressure adhesive, it is necessary to prepare the necessary auxiliary tools, adopt appropriate auxiliary technology, choose suitable adhesives, and do fine surface treatment.

 

2.4. Clamping Injection technology thru injecting leak sealing compound

Generally speaking, leak sealing compound injection technology can be used for leakage of oil and natural gas above two or three MPa and leakage of flanges, valves and other difficult positions. leak sealing compound injection technology is a mature Leakage Repairing Technology in petrochemical industry, and is also a pronoun for plugging with pressure in this industry. Because of the time-consuming disadvantage of the injection sealing technology by using leak sealing compound, it is generally the best choice to solve the oil and gas leakage.

This clamping injection technology creates a new sealing system by injecting the leak sealing compound into the prefabricated fixture and the leakage body. In the condition that the injection pressure is far greater than the leakage medium pressure, the leakage is stopped by force. This clamping injection technology can maintain a certain work sealing specific pressure and form a hard, elastic new sealing structure in a short time to achieve the purpose of repairing and stopping the leakages.

Injecting leak sealing compound technology, especially after more than 20 years' application in petrochemical enterprises, has played an irreplaceable role in the field of industrial maintanace. In order to make sure the sealing effect,during doing the jobs,we must improve the protection ability of the fixture to the leakage body, and not cause the impact of the leak sealing compound on the clamp body.

The online leak repair technology is almost the "universal technology" to solve the leakages of oil and natural gas,by injecting proper leak sealing compound. It can cover various leakage of different pressure levels, different leakage positions and different leakage media below 35MPa. With the growing maturity of this online leak repair and sealing technology, it is believed that it can be popularized in the solution of oil and natural gas leakages.

 

2.5. Illegal rapid theft technology

In recent years, because illegal elements destroy oil and gas pipelines, installing valves in oil and gas pipeline network to steal oil and gas has brought heavy losses to production units. It is a major problem for pipeline enterprises to dismantle the original features of the pipeline safely and reduce the hidden danger of the removal of gas and gas valves under the condition of non stop production. We notice that the patent product expansive occluder successfully solves this problem. Our online leak repair clamping method is suitable and good enough to seal such special and troubled leakages on pipeline without shutdown the pipeline.

 

2.6.Plugging welding technology

When the oil and natural gas pipeline leakage needs the repair of electric welding, the original method of welding usually adopts the method of cork and re welding. The safety risks of this way of operation are quite large. Most of them need to carry out fire operations, and most of them must be on fire.

We have noticed that the patent pipe plugging pliers and high temperature sealing pads can be welded on the premise of successful plugging. The local double layer plugging fixture of the patented product can also be used to plug in the welding. These technologies can ensure the electric welding under the condition of no leakage, greatly reducing the hidden danger of safety.

 

2.7.Repair technology of pipeline repair via online leak sealing technology

The leakage of oil and natural gas pipeline caused by corrosion accounts for most of the leakage. At present, the common technical countermeasures are mainly from two aspects: 1, emergency plugging, 2, replacement of pipelines. How to reconstruct the new pipeline on the basis of the original pipeline is more superior to the above two ideas, no matter from the safety production, the cost reduction and the social benefit. Therefore, the pipe network pressure repair technology has come into being.

The online leakage repairing technology for pipeline leak is to install the prefabricated tube on the pipeline that needs to be repaired. Through the pressurization process, the epoxy resin is injected into the pipeline and the resin is solidified into the pipeline, so as to achieve the purpose of non-stop production and pressure repair online by injecting proper leak sealing compound.
TSS online leakage repairing is complied with ASME PCC-2.