Identify Flooded Layer And Study On The Flooded Rule Of Low Permeability Reservoirs In The Baobei District, Baolang Oil Field

The Baobei block of Baolang oilfield, with low porosity and low permeability, is a braided river delta-lacustrine depositional reservoir of bad physical properties, great heterogeneity and difficultly exploitation. The first time of exploitation of Baobei is in 1996, and the next year the oil field begins to exploitation by water flooding. At the beginning of 2002, the production start to reduce. Because the complexity of the geology, the exploitation faces many series difficulties including: incomplete hole pattern, difficulty in adjustment, fast increasing of water ratio, low degree of pressure level maintaining, large scope of natural degression. So it is necessary to deeply study on the changing of reservoirs' physical property, to analyze the status quo of water flooded, to identify the flooded layers, and to find the rules of water flooded with the aim of helping adjusting projects.In this dissertation, the changing of producing index is discussed particularly on the basis of producing data in means of analyzing the status of production according to various layers or oil grounds or blocks. According to producing curves, the outputs reduce greatly and water ratios grow highly; the neutron lifetime log tells that the difference of vertically flooded in various districts, is not only quite great but also has character of rhythm and main production blocks has been flooded greatly, those characters are also been showed in gently logging. We studied the water injection profiles and production profiles and found that the differences of various layers are great, and by even deeply studying on the physical data found that the mainly reason is that the physical properties of reservoirs influence seeps in many degree, especially FZI, which has great relations with water saturation, water injection intensity or production capacity. In the ichnography of water distribution, the changing of water flooded zone is great, in the west and north and the east and south zones, water flooded greatly, but in the middle zones it is lightly. At the same time the distribution of water flooded zones take on directivity on the influence of deposition , physical properties and faults.Aiming at the questions of low precision of explanation using normal logging, we tried to explain the water flooded layers by qualitative and quantitative means with the principle of...