Класс Месторождения: Крупное
Тип Месторождения: Нефтегазовое
Местоположение:
Местность:
Стадия разработки: Добыча
Год открытия: 1975
Источник информации:
Метод открытия:
Площадь: 17.53 км²
Badejo oil field
The Badejo oil field is located in the central part of the Campos Basin, Brazil, with a development area of 131 km2, a water depth of 85e100 m, and about 75 km southeast of the Sao Tome cape. The Badejo oilfield is adjacent to the Linguado oilfield (LI) and the Pampo oilfield (PM) (Fig. 4). The BD-1 well that was deployed in 1975 in Badejo oilfield not only explained 15 m of net pay in coquinas of Lagoa Feia Fm. (BSW of 13%, flowed 27 API oil at a ratio of 800bbl/d (127 m3/d)), but also found huge thickness of oil layers in fractured basalt at the lower part for the first time in Brazil. The interpretation oil column is in excess of 150 m thick and the oilwater interface is clear. The testing capacity is 1356 bbl/d (216 m3/d) with flowed 33 API oil.
As for the oil reserve of the igneous rock reservoirs in this oilfield, there are large differences in different papers. For example, Tigre et al. (1983) reported oil in place for basalt of 38.262MMbbl (5.23*106 t), Baumgarten et al (1986) reported that of 35MMbbl (4.786*106 t) and Guardado et al. estimated that of 45MMbbl (6.15*106 t). The total oil in place volume of basalt reservoirs in the Badejo oilfield and the Linguado oilfield was estimated to be 9.48*106 m3 (60MMbbl or 8.20*106 t).
Reservoir characteristics
The underlying fractured basalts of the Badejo oilfield are nonconventional reservoirs. It is tholeiitic, vesicular and locally breccoidal. The vesicules are dominantly filled with zeolite. The development of natural fractures helps to remove the filled zeolite by secondary solution and to generate additional vugular pore spaces. Although the fractures are common in the Badejo field basalts, most of them frequently are filled by calcites. Locally they are found open and thus the excellent reservoirs are developed (Tigre et al., 1983). It reveal that rock facies such as vitreous basalt and breccia frequently develop better reservoir quality with megafractures than other types (Guardado et al., 1989). Some reservoir potentiality of the fractured basaltic rocks have porosity similar to pre-salt carbonate reservoirs ranges (10%-15%) in the hydrocarbon bearing intervals (Ma et al., 2011; Vieira de Luca et al., 2015). However, due to strong heterogeneity and poor continuity of fractures, commercial oil are accumulated mainly in places with high fractures and strong secondary dissolution, and often failure wells are drilled around high-yield wells (Fig. 1).
Fig. 1. Badejo oilfield igneous rock profiles (a, b) and top structure (c) (modified after Guardado et al., 1989).
Production characteristics
The Badejo oilfield was discovered in November 1975 and started producing by means of an early floating production system in December 1981 (Tigre et al., 1983; Guardado et al., 1989). The initial production of the igneous reservoir in this oilfield was 6200bopd, but the production declined rapidly, and the output reaching the stable production stage was about 2000bopd (Bruhn et al., 2003). A typical production decline of Well BD-11 from the basalt was of 1000 to 350 m3 /d in 360 days probably affected by an acting aquifer based on the pressures analysis of the reservoir against cumulative production (Fig. 6). At the end of 1982, a cumulative oil production of 213,291 m3 (1341.6Mbbl) from the basalt reservoirs was recorded.
Guardado et al. reported that average daily oil production of the field was 6837bbl (1087 m3/d), and the cumulative production was 12.9 million bbl (2.044*106 m3). About two-thirds of the total production comes from only three wells which taped the volcanic sequence. That means the basalt reservoirs of the Badejo oilfield contributed crude oil of almost 8.6 MMbbl (1.176*106 t) in 9 years.
Data source: Hydrocarbons in igneous rock of Brazil: A review. Kangxu Ren, Junfeng Zhao, Qian Liu, Jian Zhao. 2020
Следующее Месторождение: Sao Manoel