The Study Of Pattern Infilling Technology In The Middle-last Time Of Steam Soaking

The unconsolidated sandstone viscous oil reservoir of Gudao oilfield is in the middle-last time of cyclic steam stimulation,the containing water of oil well raise quickly and the decline of production increase . In order to slow down the decline of production and improve the recovery , the technical research in pattern infill must be developed . Through using geology,well logging,production test and production performance information and so on , with the technique of reservoir description , in Gudao oilfield , we reconstruct the formation,structure,reservoir,influent and three-dimensional geologic model in the heavy oil loop of fluvial facies . Through using dynamic analysis , it elaborate detailedly the production character with the influence of edge,bottom and input water . Through using reservoir engineering,numerical simulation and present value analysis to develop the distributing feature of residual oil,the technological boundary and the optimum study for pattern infill during the milled-last time of cyclic steam stimulation . The finding indicate that the influence of water invasion reduced the recovery rate and recovery . The remaining oil was concentrated in the weak invasion of water of plane,the strong invasion of water of vertial . The remaining oil of weak invasion of water was influenced by the rhythmicity and gravity , it is uniform in the bed . It adopted the different infill means in heavy oil loops. At the complete pattern in Ng5 heavy oil loop , with the straight hole , the well pattern was infilled five-spot of 141×200m from anti-nine-spot of 200×283m . At Ng6 heavy oil loop , the water-oil relation is more complex , Where the straight and horizontal holes were used . With the implementation of this program,good results were gained , the recovery of the infilled area has been advancing 10.2% and the additional recoverable reserves was about 310×104 t. This technology was important for improving recovery during the milled-last time of cyclic steam stimulation for the heavy oil reservoir.