A Look at Abnormally Pressured Formations in the U.S.S.R.

Abstract

This paper was prepared for the 46th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in New Orleans, La., Oct. 3–6, 1971. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract Abnormally pressured formations occur worldwide and are the cause of many drilling and production problems. This study takes a look at more than 100 wells penetrating Devonian, Carboniferous, Mesozoic and Tertiary formations in the USSR, in which formation pressures other than hydrostatic have been pressures other than hydrostatic have been encountered. Some data on geology, salinity and the pressure-hydrocarbon relationship supplement this discussion. Introduction A look at the world map shows that the regional structure of the Union of Soviet Socialist Republics' (USSR) land somewhat resembles that of the U.S., except that the relation of plains and mountains is reversed. A comprehensive discussion of the geology in the USSR has been given by Nalivkin. Russia's oil industry dates back to the last century, the first successful well being drilled in 1871 in the Kuban region in the Caucasus foothills. However, oil seeps in this area were known for centuries. As early as the 13th century, Marco Polo, the Venetian traveler, reported seeing caravans carrying oil from Baku on the Caspian Sea on his way to Kublai's court in Peking, China. Today, the Russians have found and developed numerous hydrocarbon deposits, with current emphasis on wildcatting in the central areas of Europe Russia and Eastern Siberia. With the exception of the Caspian Sea and possibly the Black Sea, there appears to be no possibly the Black Sea, there appears to be no hurry to develop potential offshore reserves. Existence of numerous untested onshore prospects and lagging offshore technology seem to be the main reasons. Nevertheless, during the first half of 1970 the USSR produced oil at an average rate of 6,937,000 B/D with proved crude reserves at 58 billion bbl and, according to the 1970 International Gas Industry Congress in Moscow, proved gas reserves reached 425 Tcf. The proved gas reserves reached 425 Tcf. The Russians, already leading the world in proved natural gas reserves, expect to double them in the next 10 years. Table 1 gives some additional data on drilling and production in the USSR during 1968 and 1969. OCCURRENCE OF ABNORMALLY PRESSURED FORMATIONS It is well known that abnormally pressured formations have been encountered worldwide in the search for oil and gas. Recently, Fertl, et al. listed numerous areas of known abnormal formation pressures and expressed the opinion that "increasing exploratory efforts in new areas, on- and offshore, and the general trend to deeper drilling will further broaden the areas where abnormally high formation pressures are encountered, causing drilling, completion and production problems."