Experimental Investigation of Gravity Drainage in Fractured Single and Multi Block Systems

فاقد چكيده فارسي

Gravity drainage is the main mechanism which controls the oil production in fractured reservoirs. However, fundamental understanding how oil production rate at early, middle and late times are influenced by the block height, in single block systems, and also by the number of blocks in multi-block systems are not well discussed in the avalable literature. In this work a set of free gravity drainage experiments are performed in single as well as multi-block systems which are initially saturated with the liquid phase, the production rate and height difference between liquid levels in fracture and matrix are measured at different time stages of the process. Results of single block experiments revealed that increasing block height leads to a logarithmic increase in recovery factor as capillary threshold-matrix block height ratio becomes lower. In multi-block models, lower recovery factor and lower middle time production rate are observed as the number of blocks increased. Results of this work help to better understanding the effect of block geometry on early,middle and late times production in single as well as multi-block fractured systems.