№ 10 (October 2008)
Weatherford's "Aquatic" Spreads the Gospel of Aluminiumfor Drilling Deep On and Offshore
Russia's Aquatic Co., now a subsidiary of Weatherford International Ltd., has had a long history of supplying aluminum drill pipe and risers as well as other drilling equipment.
Russia's Aquatic Co., now a subsidiary of Weatherford International Ltd., has had a long history of supplying aluminum drill pipe and risers as well as other drilling equipment. In the fact, the company has made its name both at home and abroad as a fabricator and supplier of aluminum alloy products.
“Why aluminum?” Vladimir Basovich, Aquatic's Chief Engineer, asked rhetorically during a recent interview with Oil&Gas Eurasia. “The point is that lately drilling conditions have become more complicated. Well depth has increased and horizontal drilling is more widely used. Compare these conditions with the previous practice of turbo drilling where the use of rotary and combined drilling techniques is essential. Today the total weight of a drill string is more and more critical: higher friction, loads and tension of the drill string are the functions of weight. Pure aluminum is three times lighter than steel. This is the reason why aluminum alloy drill pipes are advantageous over steel in deep, ultradeep and horizontal drilling – the drill string weight is several times less.”
“Just as an example,” Vladimir Basovich continues, “we achieved a record in Western Siberia in Megion City with the Slavneft Company. The maximum possible depth that can be drilled with the help of an old 125-ton Uralmash drill rig with steel drill pipes is 2,500 meters, or 2,700 meters at best. Using our pipes, the rig managed to drill an investigation well 4,200 meters TD. Note that using steel pipes the drilling of a similar well will require a 250 ton drill rig minimum.”
Another advantage of aluminum pipes for tubing and drilling is absolutely zero corrosion in an aggressive environment of hydrogen sulfide and carbon dioxide. All fields are characterized with higher or lower content of these substances. A year-long operation in hydrogen sulfide usually destroys any steel pipe, whereas aluminum just becomes black covered with an oxide film.
In the 1960’s and 1970’s, aluminum pipes were widely used in the USSR, and more than half of drill pipes were fabricated of this metal. At that time turbodrilling was mainly applied without drill string rotation, and the wells were not deep in Bashkiria, Tataria and Western Siberia. Those pipes had no sufficiently secure tool joint/pipe body connection. However, in environmentally sound conditions, they worked satisfactorily. Later, drilling conditions changed, and as a result, aluminum pipes of the older design failed quite often. As damage increased, the percentage of steel pipes gradually grew to nearly 85 percent. For drilling the Kolsky ultradeep investigation well (12,262 meters) at the end of the 1990s, a new aluminum pipe-body connection with the steel-tool joint was designed that made the structure more secure and the number of failures decreased. This basic design has been modernized and enhanced by Aquatic specialists.
A new design has been developed by Aquatic engineers for their clients. Aluminum alloy pipes are connected with the help of thread and steel tool joints. Aluminum hollow billets are supplied by the Samara plant, but after the plant's acquisition by U.S. company Alcoa, the prices increased and Aquatic had to switch to hollow billets produced at the Kamensk-Uralsky Mechanical Plant. Aquatic also cooperates with the Serov Mechanical Plant. Until 2004, the plant fabricated steel-tool joints for aluminum pipes and later, under the supervision of designers, the plant deployed the technology of pipe threading and is currently producing finished goods.
What is the price of these improvements? It depends on the approach. Metallurgical plants ship products in tons. A ton of pipes fabricated from aluminum alloy is approximately 30-40 percent more expensive than a ton of steel pipes. On the other hand, drillers prefer pipes in meters – if the well is 8,000 meters deep, they need a drill string 8,000 meters long. And in terms of one meter, the aluminum pipes price is equal to that of the steel pipes, and is actually just a bit cheaper.
For offshore drilling, Aquatic uses a special aluminum alloy that is resistant to corrosion from sea water. The Dutch company Fugro uses aluminum pipes from Russia for exploration drilling to depths within the range of 1,500 to 2,000 meters with the help of 30-40 ton drill rigs. With steel pipes, such a rig could drill only 500 meters maximum.
Producer Becomes a Service Company
Weatherford International Ltd. acquired Aquatic in 2008 (see www.oilandgaseurasia.com). As a result of the aquisition, Aquatic now has access to new technologies and technical support to increase its research base, and the quantity and quality of its manufacturing. The end result will be an increase in new orders.
Dmitry Basovich, who heads Aquatic's Drilling Methods and Technologies Department, explains his key targets: “We made great efforts to promote aluminum pipes for various markets. There is much prejudice related to aluminum pipes. Many people forget that 80 percent of loads are suffered by pipe due to the drill string weight, hence the load on the steel pipe is three times higher. Aluminum ‘lightens’ in liquid because its gravity is close to the drilling mud gravity.”
The Equipment and Technology Department is finalizing the design of a new aluminum pipe with external helical finning. These pipes are more often used for deviated and horizontal drilling to enhance the bottoms up process and to eliminate dune formation. To compare with the common smooth pipe that has to be rotated at 120 RPM minimum, pipe with helical fins does not require any rotation.
All Aquatic products undergo fatigue, tension and internal pressure tests. They are tested at the Krylov Research and Development Institute in St.-Petersburg which is capable of applying any type of load to full-size pipes. Aquatic also acts as a service company which, at a customer’s request, can dispatch experts to the fields, investigate well conditions and performance on-site, and suggest the solutions. Aquatic also has its own software which assists customers in selecting pipes of proper size range and design and calculates the effect of using aluminum. Feedback from after-market communication with clients lays a foundation for long-term cooperation, Aquatic managers say.
Promising research related to the development of methods of assessing the residual life of drill pipes are in the works at Aquatic's R&D Department. Currently, temporary recommendations on pipes’ scheduled inspection and replacement has been developed as the wells’ trajectories vary and drill strings perform in different conditions such as dog-leg severity, corrosivity and other factors -- and these recommendations are not precise. Hence, Aquatic specialists are trying to provide parameters helpful in identifying actual pipe life that will enable oil producers to achieve considerable savings of money and time, and to replace drill pipes and tubing in a timely manner.
Kamensk-Uralsky and Samara
The largest manufacturers of hollow billets for aluminum pipes, and finished products are the metallurgic plants in Kamensk-Uralsky and in Samara. In 2005, Samara Metallurgical Plant was acquired by the largest aluminum market player, the U.S. company Alcoa. As an Alcoa division, the Samara plant has been redesigned for export billets production. They pay less attention to oil industry pipes at the plant which can be most likely explained by the fact that this product is not widely used in the West.
After the sale of the Samara plant to Alcoa, pressed production increased for the oil and gas industry. Alcoa focused on their pipe and riser production and continued to manufacture pipes produced primarily for foreign consumers. In 2007, the first 100 tons of aluminum drilling pipes produced in accordance with API standards were shipped to the American market. Soon, specialists will seek to develop the manufacture of “hot” pipe assembly with more reliable locks. Alcoa plans to team up with VNIITNeft (Samara) and the Alcoa Technical Center (Pittsburgh) to design a new line of pipes. As a result of these and other changes, the Samara plant posted projections of an increase of sales to the oil and gas industry of up to 300 percent over the next three years.
In 2007, Samara-Alcoa sold 500 tons of aluminum pipes for the oil industry, whereas Kamensk-Uralsky Metallurgical Plant (KUMZ), through its affiliation Burilnye Truby, supplied over 7,000 tons of various aluminum pipes to its clients during a year and a half. Actually, all bids for these products are currently won by Kamensk-Uralsky producers.
Vitaly Sapunzhi, Director of Burilnye Truby Company says: “Everybody knows about the advantages of aluminum pipes due to higher specific strength, lower specific resistance factor, lower Young’s modulus and the friction factor in common drill mud, the possibility of fabricating a protective thickening and higher resistance to rust in a corrosive environment. On the other hand, aluminum pipes do not eliminate all drilling problems and shall be used in cases when it is technically and economically reasonable.” Sometimes there are conditions when aluminum pipe use is impractical, sometimes they can hardly do without them, e.g., in deviated and horizontal drilling of extended wells. Multiple companies are not able to assess quickly the practicality of aluminum pipes. It should be noted that the cost of aluminum pipes versus steel pipes per 1 meter is nearly equal. On the other hand, when aluminum pipes are recycled, a considerable part of their cost is recovered.”
Lately KUMZ has begun production of over 20 new size ranges and designs of pipes; Kumz has also applied for several patents for new technologies, designs and new aluminum alloys. An automated line for aluminum pipes/steel tool joints hot assembly, and hot assembly and packing benches for aluminum drill pipes has also been commissioned. Equipment for the ultrasonic inspection of hollow billets and cold assembly line for pipes is also being installed.
Aquatic and Burilnye Truby established a close partnership for the joint design of new pipes and other aluminum alloy products for the oil industry. Joint new design aluminum pipes production is being planned. In addition, Burilnye Truby is the key vendor of aluminum pipes for Aquatic. In general, aluminum products comprise 15-20 percent of the national market for drilling pipes and tubing. In the markets of other countries, aluminum pipes have a considerably lower share. Products of this type have not been in the market since Reynolds (the U.S. company), the producer of these pipes went bankrupt several years ago. The collapse was caused by wrong pricing and technical policy. Reynolds offered aluminum pipes on the market at inflated prices, the area of their application was not properly targeted and that contributed to the subsequent bankruptcy. Currently, Russian companies are trying to convince their Western partners of the efficiency of using aluminum in the oil and gas industry. The first results are evident. Aquatic has already supplied their pipes to Canada, Holland and New Guinea. Recently, a large lot of pipes has been shipped to China. According to Vitali Sapunzhi, Director of Burilnye Truby, a breakthrough is being anticipated. And aluminum, the metal which holds the rather unlucky position of No. 13 on the Periodic Table of the Elements, will occupy a much more lucky position in the oil and gas industry.
- Alexei Chesnokov is a staff writer for Oil&Gas Eurasia.