Fine Reservoir Description Of Shawan Formation In Middle Area Of Pai 601 Block Of Chunfeng Oilfield

Chunfeng O ilfield is located at the northeast of Chepaizi Swell,uplift in western Junggar Basin.In the middle area of Chunfeng O ilfield,Pai 601 is a super heavy oil reservoir with normal temperature,normal pressure,high porosity,high permeability and shallow layer.Problems such as channeling,water invasion,difference on the degree of reserve recovery and uneven producing reserves etc.have occurred in the development process for the reason that the current understanding cannot meet the development needs.Fine reservoir description of this area is conducted and fine reservoir geological model is established to provide a solid basis of geological study for the reasonable development and enhanced oil recovery of this reservoir.Fine reservoir description has been done based on the review of large number of documents and the summary of former research,so that understandings on the study area is updated and expanded.The target layer was classified as Shawan Formation which was subdivided into two medium-term basal levels and seven short-term basal levels.By carrying out the fine structure interpretation,there are five new eastwest trend faults;with the further description of sedimentary facies in the study area,it is discovered that sand group 1 and 3 of K₁tg¹ are characterized by braided channel sedimentary facies and sand group 2 and 3 of K₁tg² are featured by braided-river delta facies.By re-calculate reserves,compared with the original plan,oil-bearing area is increased by 0.19 km²,the geological reserves is 407×10⁴t,increased by 11×10⁴t.