Drillstring With Aluminum Alloy Pipes Design and Practices

Abstract

Abstract The up-to-date aluminum drill pipes design made it possible to develop ultra-long drillstrings for super-deep and extended reach wells. The new generation software providing for drillstring analysis including consideration of drillpipe tool joints and pads in buckling helical loads evaluation. Drill string dynamics is also taken into account. The case studies of ADP application proved their benefits over the steel ones, and recent analysis have shown an opportunity to design a super-long 15,000 m well and this was not the absolute limit. Introduction One of the most effective and recognized method of oil and gas fields development at the continental shelf, onshore remote areas, lakes, national parks and other guarded and environmental sensitive territories, is directional drilling and extended reach drilling, including horizontal section drilled in the reservoir. This method, called ERD makes it possible to reduce the number of drillsites construction, including offshore platforms, artificial islands, or other structures and to reduce the total costs of field development. In addition, it is possible to reach the reservoirs located at a considerable distance offshore from the land, and improve the environmental conditions at a well site. The ERD has a lot of technical and technological features including the drillstring service conditions as one of the most significant. The drillstring reliability plays important role in providing ERD well construction success in the whole. The drillstring assembly and weight as well as the assembly and weight of individual section thereof influence the possibility of drilling in accordance with the designed borehole path. The choice of drill pipe material and drillpipe geometry becomes very critical in that respect. The consideration of aluminum alloys, as the most prospecting material for drillpipes in that circumstances is the subject of this paper. The aluminum alloys advantages are shown both in the calculation and practical use for different well scenarios. Aluminum Drillpipes: Background Specific physical and mechanical properties of aluminum alloys ensuring high strength-to-weight ratio combined with good corrosive resistance in some aggressive environment and their adaptability to manufacturing various products has led to their wide use in oil and gas industry. Since the late 1950s Russian research centers have done extensive research and development works resulted in development, full-scale manufacturing and widespread use of aluminum alloy drill pipes in domestic industry. LBT is the Russian acronym for this product, which mean "Light-alloy drillpipe", we suggest here to use LADP as English acronym, but in many previous cases "ADP" acronym has been used as well. Samara Metallurgical works and Kamensk-Uralsky Metallurgical works have arranged special shops to produce LADP since 50s. The shops included the equipment designed for manufacturing pipes of various cross sections lengthwise. The research and development activities involved the following:investigation of materials with suitable physical, mechanical and operational characteristics that would fully meet the deep and ultra deep drilling requirements,development and experimental works associated with extending LADP grades and their manufacturing process,design and production of the equipment for LADP production,construction of specialized shops for LADP full-scale production,design procedure for drill string assembly of LADP for drilling under a variety of borehole conditions. These efforts have allowed for developing and introducing into production a wide range of LADP with some 80 standard sizes. The design was developed to use all benefits of LADP with taking into consideration the basic equipment of metallurgical production.