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The M6 Steam Drive Project Design And Implementation

1977; Society of Petroleum Engineers; Volume: 16; Issue: 03 Linguagem: Inglês

10.2118/77-03-04

2156-4663

A.J. Herrera,

Hydraulic Fracturing and Reservoir Analysis

Abstract The M-6 steam drive project is located in the Tia Juana field, Bolivar Coast, Venezuela and is scheduled to go on stream towards the end of 1977. Primary production started in 1948 followed by a period of stea1n soak from 1969 onwards. Steam soak is favoured by the compaction process. At the start of steam drive it is estimated that the remaining reserves by compaction is some 4% STOIIP compared to a total recovery by comparison of some 20% STOIIP. The past performance amt the prediction of future performance will be discussed on the basis of the results obtained from an earlier, smaller scale steam drive project, laboratory investigations on physical models and compaction drive theory. During 1975 and 1976 an extensive programme of data gathering in the field and special production/ injection tests in wells were carried out, and a detailed geological/petrophysical study is being made. In three inverted seven spots steam is being injected continuously, the first hexagon started in November 1975 and the other two in July and August 1976. Tracers in the gaseous and aqueous phase have been injected to detect preferential flow. The results of these tests a1'e discussed. Introduction The heavy oil fields on the eastern coast of Lake Maracaibo (see Figure 1) - known as the Bolivar Coast -initially contained some 33.8 billion barrels of oil-in-place, of which only about 11% can be recovered by primary means; this figure represents an average which comprises 0% recovery for the very viscous crudes (up to 50,000 cp) in North Tia Juana, 6–7 %, in the Upper Lagunillas Heavy and up to 20% in the coastal areas. The current proven and possible reserves by primary and steam soak production is on average 18% STOIIP, therefore leaving in the ground some 28 billion barrels of oil as a vast potential for additional recovery methods. Since 1959 various methods have been tested, such as steam drive 1,3, in-situ, combustion2 and steam soak.4,5. Reservoir compaction is the main production mechanism in the Bolivar Coast reservoirs. It is proposed to make full use of this natural source of energy by applying the steam soak process. When compaction reserves are exhausted, other drive processes will be applied; the most appropriate being steam drive based on pilot tests. The M-6 steam drive is intended to evaluate the application of this recovery method on a large scale as the follow-up process for the Bolivar Coast after steam soak. Based on the results of laboratory experiments and the performance analysis of the C-3/C-4 steam drive test, discussed below, the large scale M-6 steam drive project has been designed. LABORATORY MODEL EXPERIMENTS Physical model studies were undertaken in 1971 in the Koninklijke/Shell Laboratorium. Rijswijk, the Netherlands, to obtain additional technical information on the steam drive process under Bolivar Coast heavy oil reservoir conditions. The investigations took place in one twelfth of an inverted seven spot proto-type (closed hexagon) with a distance of 230 m from corner well to centre injection well.