Research And Application Of Water Channeling Control Technology In Shinan Block

The low permeability reservoir of Shinan Block TH formantion has the characteristics of large physical changes in strata heterogeneity in layers.In the production process,the water channeling is serious and results in water cut rising fast.Water plugging and profile control technology plays a key role in controlling water production and stabilizing oil production.It plays a great role in improving reservoir development efficiency and improving oil recovery and utilization rate.From reservoir lithology and sedimentary microfacies characteristics,based on the study of the distribution of water flooding channels and residual oil,this paper has developed the study on the oil well water plugging decision technology,established the qualitative identification,quantitative description and quick judgment method of water channeling.Through experimental evaluation,a series of plugging agents and supporting working fluids suitable for Shinan Block have been selected.Based on the evaluation of the existing selective injection method,the water control technology suitable for low porosity,low permeability and medium fine throat reservoir in TH formantion was determined.The optimum plugging radius is 0.08~0.2 times of well spacing.For the layers where the starting pressure difference between high permeability and low permeability reservoir is larger than 4MPa,the separate-layer water injection and profile control technology are recommended.The hydrophobic associative polymer AP4 was used as the main agent of gels.For small flow advantage channels,the 0.25% polymer + crosslinking agent A 0.12%+ crosslinking agent B 0.03%+ stabilizer 0.1% was adopted.For large water channel,the polymer 0.4% + crosslinking agent A 0.15% + crosslinking agent B 0.035% + 0.1% stabilizer was used.The jelly was made of phenolic resin 0.9% + polyacrylamide 0.4%;The particle adopts the flexible steering agent BG-Spring or polymer microsphere,with a concentration of 1500mg/l,and the sulfonate anionic surfactant sy-1 was used as preflush.The profile control technology has been carried on 53 wells in 43 well groups and the water plugging technology has been implemented in 29 wells.The effective rate of these measurements is up to 78%.The producing efficiency of water absorption profile has increased from 63.8% to 69.1% and the water storage ratio increase and remain to 65% from less than 50%.Additional producing oil is up to 35269 tons,the input-output ratio is 1∶4.After carrying out these measures,the production profile in oil well and absorption profile in injection well have increased significantly.It realized the aim of controlling water breakthrough channel,reducing water cut increasing rate and improving the oil recovery.