Extra Heavy Oil Whole Steam Channeling Prevention Technology Research

At cyclic steam stimulated stage,with the extension of production time,super heavy oil reservoir's reservoir pressure declines,and gas breakthrough phenomenon becomes serious.These problems affect recovery effect of block seriously.How to prevent gas breakthrough,ensure effective exploitation of oil wells,and enhance fault block oil reservoir's recovery ratio become an important Issue of field production.Following deepened super heavy oil development in Du 229 Block of Liaohe Oilfield,oil wells' cyclic steam stimulated has already entered medium-high round production stage.For high round,poor efficiency,serious gas breakthrough and other development conflicts get more and more complicated,cyclic steam stimulation of single well hopes to further Improve recovery degree is very difficult.According to production,the paper analyzes the essence of gas breakthrough.Using present technology and combining with principal anti-channeling technology at home and aboard,such as common injection&common mining technology,chemical plugging technology,and shut in gas breakthrough well technology,develop various technology means to carry out comprehensive treatment to Du 229 Fault Block,such as profile control sealing channeling,mechanical sealing channeling,falling rate injection anti-channeling,one-well injection&multi-well production,regional steam injection,separated layer steam injection,intermittent steam injection,and so on.And gradually change from single well to the combination of multi-wells cyclic steam stimulated mode.According to well distribution,perforated interval situation and gas breakthrough relation,we divide the block into several symmetry elements,and carry out overall,orderly and central injection and omnibearing stereoscopic heating to the symmetry elements.Using interwell gas breakthrough passageway,through maintaining steam injection pressure balance,control and avoid interwell gas breakthrough,and retrimming temperature field,pressure field and oil saturation field to further enhance block's recovery degree.This method plays a part to improve development effectiveness of the block and has remarkable economic effect.It also reaches certain conclusions of controlling gas breakthrough,and provides experience to prevent gas breakthrough in heavy oil recovery.