The Study On Development Method Of Asynchronous Injection-production In Vertical Volume Fracturing Well In The Extra-low Permeability Reservoir

At present,the extra-low permeability reservoir in China adopt waterflood development,which is not very effective.After volume-fracturing,the well production rate can be improved to a certain extent,but there are problems such as rapid decline and rapid water flooding,which seriously affect the effective development of extra-low permeability reservoir reservoirs.Thus,a set of development method of asynchronous injection-production in vertical volume fracturing well in the extra-low permeability reservoir has been put forward.Namely,the two stages: volume fracturing depletion development and asynchronous injection-production development.At first,in order to figure out the development mechanism of the technology,this technique is divided into two stages.Then Using reservoir engineering and numerical simulation methods,the matrix permeability fracturing numerical model,volume of depletion development model and asynchronous injection-production development model has been built.Based on these model,the different stages of development mechanism and the influencing factors has been studied,and the imbibition mechanism has been described.It is believed that the imbibition process in volume fracturing depletion development and asynchronous injection-production development can both improve the development effect of reservoir.The longer the shutin time,the stronger water wettability,the higher capillary force and the small fracturing spacing can effectively play the imbibition effect of the matrix.At the same time,the asynchronous injection-production process can effectively supplement the formation energy and improve the water flooding area.Then,based on the application of the technology,optimization of the fracturing technology and injection-production parameters,it’s believed that this technique in medium-strong non-homogeneous formation can get good development effect.At last,using parameter optimization results,the asynchronous injection-production in vertical volume fracturing well can effectively improve the recovery efficiency of extra-low permeability reservoirs.By using this technology,the problems such as the dramatic decrease of extra low permeability reservoir in the prophase,injection wells and production wells’ difficulty to establish an effective displacement,and the existence of lots of the low-productivity wells have been effectively solved,and the imbibition between injection medium and matrix has been fully used.The work of this paper provides an important technical reservation for the effective development of extra low permeability reservoir.