Published December 2009

Production technology of plastic oilfield pipes

M.M.Gurbanov

The investigation of the plastic pipes formed by metal pipes being tied around with the fiber glass in laboratory condition showed that they are of great endurance in any aggressive surroundings which create corrosion in oil-fields. Because these pipes made in a plant condition were used as dielectric details in electro-technological industry, there was need to change the preparatory technology in order to achieve the use of them in oil-field circumstances, to prepare new technological arrangements. And also it was necessary to select the temperature and pressure conditions, to optimize the expenditure quantity of raw materials, in a word to organize the production of the pipes that are suitable for the application in oil-field circumstances. First of all, the work principle of winding machines form the pipes was changed. There also was a change in the expenditure of raw materials. The inner diameter of a plastic pipe which will be prepared is appropriate to the outer diameter of the metal pipe. After extracting the plastic pipe from the metal pipe, the bracelet part remains as it is, another part is threaded by cutting. The pipe is dried after being formed. This process consisting of 7 parts is conducted in special stoves. Further, the durability of the hydraulic of the pipes to the tension is checked. The hydraulic of the testing work takes place in the stand. The outer threads of the pipes firstly are checked in a visual way, then in a practical way. The conicity of the outer and inner threads are checked by the use of the smooth gauge-ring and gauge-plug. The limit of ability to swallow water doesn’t get over the 0.1% at 20 oC during 24 hours. The dependence of the plastic pipes on temperature indicates that no changes happen in the pipes up to 150 oC. Then, the structure of the pipe begins to be disturbed as it is heated over the temperature aforementioned. When we compare the plastic pipes with the carbonic steel, stainless steel and aluminium, we see that the plastic pipes being lighter 4,4 -5,2 times than the steel pipes, 1,6 times than aluminium are superior for their coefficient of lined expansion, stability limit in tautening, module of elasticity and other indicators. The pipes made in Mingachevir IZOLIT plant have been tested in both dry land and sea oilfields of SOCAR. At the time of experiment the oilfields with the high corrosion aggressiveness have been chosen. The pipelines transferring oil through the plastic pipes having the length of 25 km and various diameters have been constructed. According to conditions the period of exploitation is calculated up to 30-40 years.