Abstract

Bombay High oil field has two oil pay zones L-II and L-III and one gas pay S-1. L-III is the main oil pay and is taken up for development, initially in the northern part of the field. It is a layered reservoir with a thin oil column and a gas cap. The reservoir rock is a micrite with intergranular porosity and minor secondary porosity in the form of vugs and solution channels.

Development of the oil field is faced with the problems of a thin oil column over a wide area and shallow depth of the reservoir. Based on reservoir studies, platform locations were chosen at a distance of 3 Km. Wells in two rows, for A1 and A2 layers of L-III pay, were to be drilled. 5 platforms were to be installed and four wells, two wells for each of the two layers, were to be drilled from each platform. To avoid edge gas coning, the row of the wells is to be at a distance of 2 Km. from the outer oil gas contact of a layer.

Of the 5 platforms installed (A,B,C,D and E), two (A and C) are well-cum-production platforms. Each production platform is designed to handle 40,000 bopd. The first and second stage gas from the production platforms is mixed and sent to flare jacket near ‘A’ platform. Oil from ‘C and ‘A’ production platforms is pumped to a storage tanker ‘Jawaharlal Nehru’ through a storage SBM connected to platform ‘A’ by sunsea pipeline. The oil is transferred to a tanker for transporting to Bombay refineries.

Two trunk pipe lines, 30″ for oil and 26″ for gas are planned to be laid over a distance of 220 km. from Bombay High oil field through Bassein oil field to an oil and gas terminal at Uran near Bombay. The pipe line will be able to transport 18 million tonnes of oil per annum and 7.5 million cubic metres of gas per day. These pipelines will be able to transport not only the oil and gas from Bombay High and Bassein fields after their full development, but also the oil from new discoveries.