The Optimization Research Of Layer And Well Pattern Recombination Of Waterdrive Reservoir In Super High Water Cut Stage

After overyesrs waterflooding, most maturing field has entered into super high water cut stage with water cut reaches 90%, the effection of reservior vertical and areal heterogeneity has been more seriously, so the preexisting layer system and well pattern are not adapted to the requirement of enhancing recovery, the layer recombination and well pattern optimization is very essential to excavate potentiality deeply.Heterogeneity is the dominant factor which affects development effect in super high water cut stage, the affection of interformational heterogeneity was researched by one dimensional water/oil immisciblely driving theory, and we find that the model recovery decreases 17% with the permeability contrast increases from 2 to 10. Based on the effective block—Shengtuo field second region 4-6 sand group, a concept model was built and the political limit such as permeability contrast, crude viscosity, flow coefficient, sublayer numbers and delta depth was delimited. The upper limits of effective thickness and sublayer numbers was obtained by the analysis of field material.The advisable layer division and recombination is the chief method to increase flooding producing degree and swept volume. The remaining oil pattern of integrity reservoir in super high water cut stage was researched by simulation software Eclipse and the fuzzy cluster analysis was inducted to classify the eighteen layers according to semblance. The recombination schemes for Shengtuo field were made based on the foregoing two research and the numerical simulation research, technology and economic assessment was proceeded. In addition, the recombination principle was summarized, the viewpoints such as compromising technology and economic viability sufficiently, optimizing scheme which has smaller implement difficulity were proposed.Based on layer recombination optimization, the water injection mode and well pattern thickening were researched. The regular well pattern was chosen to raise pattern coverage and decrease the plan divergence. The technology limiting well spacing density is 52.5m×62.5m (well spacing×line spacing), the corresponding control degree is 99% and recovery is 59.59%. The advisable well spacing is 105m×125m at the present price based on the economic assessment. So this treatise has important value for guiding the exploitation potentialities of integrity reservoir in super high water cut stage.