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Light-weight flexible pipe is needed for deep-water offshore oil fields, but there is a limit to the depth at which conventional flexible riser pipe can be used. In this paper we first describe the concept of the limits of applicability for conventional flexible riser pipe and discuss trends in and methods for making it lighter-weight. Then, because the use of fiber reinforced plastic (FRP) for the tensile reinforcing layer is considered the most effective and practical way to lower the weight of pipe, we discuss the conditions and characteristics for FRP for use in the reinforcing layer of FRP riser pipe, as well as the design, manufacturing, and evaluation of FRP riser pipe. Introduction As shown in Figure 1, flexible riser pipe consists of an interlocked conduit, an inner plastic pipe, hoop stress reinforcement, tensile reinforcing layer, and an external sheath.1')2)3) Such pipe has come to be widely used in offshore oil fields, where it has become an essential item. As deeper offshore oil fields are developed, this pipe is being used at greater depths. By 1992 oil fields laying 850 m underwater are under developments) and the future is expected to bring the development of offshore oil fields at even greater water depths. Weight is an important factor in floating production systems, and research and development is being carried out in order to create lighter-weight TLP tethers and rigid risers.4) The use of flexible riser pipe in such deep-water oil fields causes problems of increased laying tension and increased side wall pressure due to the weight of the itself. This has led to the development of methods for installation at great depth5)6and the development of lighter-weight flexible riser pipe.7) Study is underway for replacing the reinforcing layer of light-weight flexible riser pipe with aluminum or a composite material (FRP). Meanwhile, the use of stronger reinforcing steel and the use of FRP are being considered to solve this problem, and this paper discusses the use of FRP. Key problems The depth at which flexible riser pipe can be used is limited by the allowable tension and the laying side wall pressure, which depend on the weight of the pipe itself. As shown in Figure 1, flexible riser pipe has a structure in which a plastic pipe is reinforced by multiple layers of metal. The greater the depth at which the pipe is to be used, the greater its weight must be, and therefore the thicker its tensile reinforcing layer must be, but this produces even greater weight, requiring even greater thickness, in a vicious cycle that imposes design limits. To ascertain the characteristics of the tension of flexible riser pipe in the depths of the ocean, we analyzed the fluctuations in tension produced by waves in a free hanging configuration. Here we considered the maximum static movement assumed for a semi submersible platform and the dynamic response for a significant wave height of 18 m and a period of 15 see, while the pipe is subjected to the use pressure.

Produced water is any water that is present in a reservoir with the hydrocarbon resource and is produced to the surface with crude oil or natural gas. The major components of produced water are oil, grease, TDS, many organic and inorganic compounds. These components vary greatly from location to location and even over time in the same well. For Iraqi petroleum fields, the produced water in most cases is discarded into evaporation ponds outside the fields and this causes serious environmental problems for air, soil, and ground water. On the other hand, huge quantities of treated fresh water from rivers are used for injection in the petroleum wells to increase the productivity of petroleum fields from the oil in so called Enhanced Oil Recovery (EOR). A prediction study conducted by South Oil Company (SOC) indicated that the production rate of produced water in North Rumaila field varies (290000- 800000 BBL/day) from 2011 to 2028. For the above mentioned reasons, a joint research team from Petroleum Research and Development Center (PRDC) and SOC has formed to find solutions for produced water treatment to be suitable for reinjection purposes. In the beginning of 2010, a memorandum has been signed between Iraqi side (PRDC) and Japanese side (JCCP, WRPC, SWING) to start a joint project of PW treatment for reinjection application. Iraqi side collected the data related to the quantities and qualities of of PW in SOC, determined the required specifications for re- injected water and also selected the PW of South Rumaila field (Degassing Station NO.1) to be treated for reinjection. The joint research team (Iraqi & Japanese) hold several technical meetings to identify the PW problem and put the more suitable technology for treatment. The general philosophy of treatment was agreed by the the joint research team. SWING Company has adopted construction of a pilot plant (total capacity 10m3/day) to test the efficiency of the proposal treatment on ARTIFICIAL PW. Iraqi side provided the Japanese side with the types and concentrations of salts that required to prepare an ARTIFICIAL PW with similar properties of natural PW.Two Iraqi persons have been delegated to Japan for one month for training on installation and operation of pilot plant. After acquiring the skills of installation and operation by Iraqi operators, the pilot plant has been shipped to South Rumela field (Degassing Station NO.1) and installed by Iraqi operational team. The obtained results of the treated PW properties by the pilot plant were very good and met to the required specifications of water for reinjection.

This paper introduces a new welding robot system used in the construction site.This system is able to perform welding all around the columns by using laser sensors. The shape of the groove is determined by laser sensors and welding conditions are determined for horizontal welding position.The considered application is a horizontal position multi-layer welding of box column to column joint with single bevel groove. The entire system consists of a laser sensor, the robot, a slag removing apparatus, a nozzle cleaning apparatus and a carriage that is loaded with all the mentioned equipment.

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