Technology and Application on Reservoir Architecture Characterization Based on Sandbodies Spatial Orientation

Abstract

As the high percent of effective sandbody thickness, the braided river reservoir becomes an important exploration and exploitation area. The Shihezi group lower eighth section of Sulige gas field is a typical sandy braided river reservoir. Strong reservoir heterogeneity is the main restriction factor of gas field development. Su X adding area, for instance. Reference to the analysis results of modern sedimentary and ancient outcrop configuration, a new reservoir architecture characterize method is put forward. The new methods realize river channel sandbody spatial orientation by “changes on bottom of sandbody and microfacies overlay regular pattern” and realize channel bar sandbody spatial orientation by “logging cycle, silt layer position, and microfacies overlay characteristic.” The reservoir structure analysis on river channel and channel bar has carried out, and the effective sandbody control effect from reservoir configuration unit has analyzed. The characterization results show: ① There are two main plane combinations in the single channel sandbody of Shihezi group eighth section in research; they are banded channel whose width is 1000–2000 m and sheet scale channel whose width is 1500–4000 m. ② The main reservoir configuration units include the channel bar, braided river channel, and flood plain, and the channel bar is the main reservoir element. ③ The sandbodied scales are different because of different genetic type. The thickness of channel bar always is 3–5 m, the width is 250–300 m, and the length is 500–900 m. The width of braided river channel is always less than 200 m. The deposition pattern presents “alternate channel and bar, wide bar and narrow channel” on flat. ④ Five-level configuration units control effective sandbody macro-distribution, four-level configuration units are the main control factor, and three-level configuration units have little effect on the distribution of effective sandbodies. The method has been successfully used on well location optimization in Sulige gas field. It have reference value to the same type Reservoir configuration analyze.