Scaling Problems in Western Siberia

Abstract

Yukos Oil Company is the second largest oil production company in Russia, and produces 1.2 million barrels daily, with > 60% of this coming from fields in W. Siberia. Base oil and gas production units are located in the European part of Russia (OAO Samaraneftegaz) and W. Siberia (OAO Yuganskneftegaz and OAO Tomskneft VNK) [1]. This production comes from a variety of fields, and it is common for these fields to produce at significant water cuts. Produced water leads to several production and cleanup problems (since it is also re-injected), one of these being the problem of mineral scale. The most common scale is calcium carbonate and this is found in both mild and more severe scaling cases. Sulfate deposits are present too in minimal amounts. However, a feature of the W. Siberian reservoirs is that they have many thousands of wells. Therefore, although the technical problem of treating a single well may not be large, the approach and logistics to protect such a large number of wells is a significant challenge. In this paper we survey the problems of scale in these W. Siberian fields and we outline how Yukos has approached this challenge. Introduction Two production units, OAO Tomskneft and OAO Yuganskneftegaz, carry out the main oil production in Western Siberia on the territory where Yukos has licenses. Fig.1 shows the geographical placement of Yukos's main production and refining units. A brief description of them is presented below. OAO Tomskneft VNK. OAO Tomskneft VNK is the principal Production Association of Yukos subsidiary OAO "Vostochnaya nefteyanaya kompanya", also known as VNK or the Eastern Oil Company. Established in 1966, Tomskneft VNK has produced more than 2 billion barrels of oil since it began its operations. 21 fields are currently under development or in production. Tomskneft VNK operates in the remote western part of the Tomsk Region in Western Siberia. Some of its more unusual assets include its own fleet of river barges and approximately 1,000 kilometers of service roads. Since over 70% of its recoverable reserves fall into the "difficult recovery" category, Tomskneft VNK has introduced advanced technologies for horizontal drilling and deep hydraulic fracturing of formations. It has also begun to acquire additional licenses for the development of several new areas in the Tomsk Region. At present there are 1880 production and 840 injection wells in operation. The average oil rate is 170 bbl/day, and the average water cut is 65%. OAO Yuganskneftegaz. OAO Yuganskneftegaz is the Yukos Oil Company's largest Production Association - and the second largest in all of Russia. Yuganskneftegaz, located in the Khanty-Mansi Autonomous Area of Western Siberia, first began operations in 1964, and has produced over 9 billion barrels of crude to date. At present, Yuganskneftegaz manages 29 fields, the largest of these being Priobskoye, Prirazlomnoye, Mamontovskoye, Malo-Balykskoye and Salymskoye. The Priobskoye field is unique as to its geological structure. Recoverable reserves are estimated at 3.01 billion barrels. Prirazlomnoye has 2 billion barrels reserves; a three-dimensional seismic survey of the field has revealed the existence of promising areas that could significantly increase production there. In order to improve well operation, Yuganskneftegaz is introducing hydraulic fracturing and implementing a program to increase efficiency and reliability at its production sites. The program includes improving the power supply system, purchasing additional up-to-date well equipment, and establishing a network of production supervisors. At present there are 6000 production and 2300 injection wells in operation. The average oil rate is 169 bbl/day, and the average water cut is 71%. OAO Tomskneft VNK. OAO Tomskneft VNK is the principal Production Association of Yukos subsidiary OAO "Vostochnaya nefteyanaya kompanya", also known as VNK or the Eastern Oil Company. Established in 1966, Tomskneft VNK has produced more than 2 billion barrels of oil since it began its operations. 21 fields are currently under development or in production. Tomskneft VNK operates in the remote western part of the Tomsk Region in Western Siberia. Some of its more unusual assets include its own fleet of river barges and approximately 1,000 kilometers of service roads. Since over 70% of its recoverable reserves fall into the "difficult recovery" category, Tomskneft VNK has introduced advanced technologies for horizontal drilling and deep hydraulic fracturing of formations. It has also begun to acquire additional licenses for the development of several new areas in the Tomsk Region. At present there are 1880 production and 840 injection wells in operation. The average oil rate is 170 bbl/day, and the average water cut is 65%. OAO Yuganskneftegaz. OAO Yuganskneftegaz is the Yukos Oil Company's largest Production Association - and the second largest in all of Russia. Yuganskneftegaz, located in the Khanty-Mansi Autonomous Area of Western Siberia, first began operations in 1964, and has produced over 9 billion barrels of crude to date. At present, Yuganskneftegaz manages 29 fields, the largest of these being Priobskoye, Prirazlomnoye, Mamontovskoye, Malo-Balykskoye and Salymskoye. The Priobskoye field is unique as to its geological structure. Recoverable reserves are estimated at 3.01 billion barrels. Prirazlomnoye has 2 billion barrels reserves; a three-dimensional seismic survey of the field has revealed the existence of promising areas that could significantly increase production there. In order to improve well operation, Yuganskneftegaz is introducing hydraulic fracturing and implementing a program to increase efficiency and reliability at its production sites. The program includes improving the power supply system, purchasing additional up-to-date well equipment, and establishing a network of production supervisors. At present there are 6000 production and 2300 injection wells in operation. The average oil rate is 169 bbl/day, and the average water cut is 71%.

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