The Recovery Evaluation Of Underbalanced Flowback Of Overbalance Water Influx Damage In Dual Media

Tight sandstone and carbonate rocks are dual media features,nvasion damage by water in the over-balanced drilling process,the dry gas to western Sichuan Xujiahe Tibet owed the balance can not flowback recovery,while the to Jidong Austrian pottery Departmentcarbonate as the representative of gas condensate reservoir underbalanced flowback restore thus,to solve this problem,based on the research of formation damage,to carry out research and analysis of a dual medium reservoir of potential geological damage factors,the type of damagecomparison and analysis of the extent of damage, with concrete examples,research and analysis,the dual medium reservoir water influx to the extent of damage and the underbalanced flowback to restore the ability to carry out the quantitative evaluation of double based on fluid mechanics in porous media flow theory,namely the establishment of a balance in order to furtherbalance drilling segment over the balance of water influx and less balance back to the emission calculation model,dual media reservoirs balance with the water influx in the drilling process,and owe the balance back to the emission calculation model,the cracks in the system pressure,water saturation degree.distribution block water saturation distribution block gas relative permeability distribution.blocks the extent of the damage distribution blocks and cracks as well as the dual media reservoir water influx and return displacement of a series of evaluation parameters,on the doubleto evaluate the extent of damage and recovery capabilities of the media.After the systematic theoretical studies and laboratory experiments evaluation,This paper gets the following main results:Based on the characteristics of the dual medium reservoir,combined with comparative analysis of specific instances,to improve the method of dual medium reservoir geological characteristics,Western Sichuan Xujiahe Seccond State dry gas reservoir and Jidong Ordovicianrepresented by deep marine gas condensate reservoir potential geological damage factors.Laboratory evaluation experiments carried out to be home river.Sec dual media reservoirs in western Sichuan,Jidong Ordovician carbonate dual medium reservoir type of damage and the extent of damage and,ultimately,these two dual media in balance damage after flowback recovery capability exists to the understanding of the difference.Based on air-water two-phase flow theory,the establishment of a mathematical model for overbalanced state,expand the following three aspects:①the same penetration,the same differential pressure conditions,water influx.and the crack density the same;②fracture permeability,the same positive pressure conditions,the water influx to the relationship between distance and fracture density;③The same permeability,the same pressure,under the conditions of the same invasive capacity,water invasion of the relationship between distance and fracture density.Water influx and less balance back to the emission calculation model for overbalanced in underbalanced drilling segment to carry out the quantitative study of the reservoir intervals over balance damage and under the law of balance flowback,and western Sichuan to be the home river,Sec dual media reservoirs.Jidong Austrian Ordovician carbonate dual medium reservoir,for example,the negative pressure of the two dual media reservoirs to restore the ability to carry out a quantitative evaluation and research results show that the dual media of the Jidong Ordovician carbonate reservoir backflow effect isgood recovery ability,and western Sichuan to be home river,Sec dual medium reservoir is difficult to flowback serious reservoir damage.Water influx and under the balance back to the displacement calculation model is established for overbalanced with the drilling process.Quantitative research carried out for the invasion of the law and under the law of balance flowback overbalanced with the water in the drilling process.and the western SiChuan to be the home river, Second State dual media reservoirs,Jidong Ordovician carbonate dual media reservoirs as an example.two dual media reservoirs ability to recover balance with the water influx and negative pressure in the drilling process quantitative evaluation and research.