Integrated Evaluation Approach of Reasonable Bottom-Hole Flowing Pressure of Oil Wells

Reasonable bottom-hole flowing pressure is the guarantee for the full play of oil wells’ productivity and improvement of oilfields’ development efficiency,but an accurate,reasonable and integrated evaluation approach is not available yet on well site.Based on the analysis on the influence of produced gas oil ratio,sand production,stress sensitivity and interlayer interference on reasonable bottom-hole flowing pressure,a mathematical model of integrated evaluation approach of reasonable bottom-hole flowing pressure was built using the principle of fuzzy transform.The mathematical model can do caculation considering the impact of different factors and different factor weights.The calculation and analysis of actual example showed that the evaluation approach of flowing pressure proposed in this paper had high calculation accuracy.This could provide theoretical guideline in reasonable flowing pressure design and proration production.In addition,the sensitivity of reasonable bottom flowing pressure to permeability variation coefficient,oil gas ratio,Poisson’s ratio and other parameters were analyzed with real field data.The results showed that: for reservoirs with high permeability variation coefficient,high reasonable bottom-hole flowing pressure should be maintained in order to keep the reservoir’s seepage ability;For the wells with high produced oil and gas ratio,high reasonable bottom-hole flowing pressure should be maintained to ensure the pumping efficiency;High reasonable bottom-hole flowing pressure should be kept for unconsolidated sandstone with high Poisson’s ratio in order to prevent sand production.