Study On Completion Technology Of Horizontal Well Tuning And Water Control

Bottom water coning is always an important problem faced in the development of the bottom water reservoir. The inflow profile along horizontal section of horizontal well is not uniform distributed because of the factors such as the "Heel Toe Effect" of the horizontal well, the heterogeneity of the reservoir and so on. Bottom water breakthrough caused easily in the heel section or high permeability segments. This may lead to the local flooding in the well and well shut down. In order to solve this problem, scholars developed the inflow control completion method of horizontal well to control and relieve the bottom water coning in the bottom water reservoir and to further tap the potential of horizontal wells. A large number of foreign field applications indicate that inflow control completion method played a good effect in dealing with bottom water coning. Since the ICD is a passive control device and once put into production cannot be adjusted, its completion parameters have to be designed accurately according to the characters of reservoir and horizontal well. This thesis is to optimize the development effectiveness of the bottom water reservoir by using inflow control device, Investigating the operating principle of ICD, Set up a mathematical model of the ICD completion parameters. Formed a ICD completion parameters calculation method, as well as the adaptability evaluation method eventually.In order to analysis the inflow profile of conventional horizontal well, Reservoir and wellbore coupling model is built in this thesis, based on Engineering Fluid Mechanics and Seepage Flow Mechanics, calculated by using Gauss iteration method. The result indicates that the production inflow profile of horizontal well is uneven distribution; the bottom water is easily breakthrough in the toe in homogeneous reservoir and also shows that the effect of flow pressure drop in horizontal wellbore cannot be ignored.Second, analyzed the structure and the mechanics of ICD, summarized the regulating characteristics of different types of inflow control device, analyzed the reason of bottom water break-through, concluded that bottom water could uniform distributed by controlling the sand surface pressure along the horizontal. Put forward the parameters design method of ICD well completion adapted to the homogeneous and heterogeneous reservoirs combined with reservoir wellbore coupled model:In the homogeneous reservoir, the calculation of the additional pressure of the ICD is to balance the sand surface pressure; In the heterogeneous reservoir in order to achieve the uniform distribution of producing profile for calculate the additional pressure. The calculated results show the inflow control device can balance the inflow profile of horizontal well, but because of the limit effects of pressure, the productivity of ICD completion horizontal well was reduced compared with the conventional completion.Final, analysis of production characteristics of horizontal well in different reservoir and wellbore parameters, it shows that the thicker the reservoir is, the higher the permeability is, the smaller the wellbore diameter and the longer the horizontal section is, the flow drop pressure in horizontal well is greater, the ratio of flow drop pressure and production pressure is bigger,"Heel Toe Effect" is more obvious. As the horizontal well productivity is greater, the flow pressure drop is higher, The effect of ICD is more obvious, When the ratio of flow drop pressure and production pressure is greater than0.1,the productivity of horizontal wells changes smaller.Using time prediction model of bottom water breakthrough analyzed the conventional completion Well and ICD completion Well. The conclusion is the longer of horizontal section, the higher height of water avoidance and the higher the ratio of vertical permeability and horizontal permeability is, the time of bottom water breakthrough in horizontal well with ICD is longer.