New Dynamic Multi-factor Economic Limit Well Pattern Density Calculation Method Based on Single-Well Limit Control Reserves

Abstract

There are two kinds of traditional methods to calculate the economic well pattern density: One derives from the single-well limit control reserves, and the other derives from the relationship between well pattern density and recovery factor. After they are combined with some economic evaluation parameters, a static or dynamic method is used to calculate economic limit well pattern density such as Yu Qitai method, statistical analysis method, intersection method, net present value method, and the modified single-well limit control reserve method. But these methods cannot fully consider all the economic parameters, the time value of money and production decline, etc. In order to make up for the inadequacy of existing methods, a new calculation method of multi-factor economic limit well pattern density is established based on the single-well limit control reserves by using dynamic economy method. This new method not only considers the total investment of oilfield development, but also considers annual crude oil sales revenue, the annual operation cost and interest, annual price and cost floating and production decline and so on in the main development period. This method is applied in the economic limit well pattern density calculation of block A in Daqing Placanticline periphery oilfield. The results show that at the crude price of 60 dollars/bbl, the economic limit well pattern density is 30.79 wells/km2 and we can drill the infilling wells in the number of 212. Meanwhile, the predicted incremental oil recovery is 5% and the increased recoverable reserves are 4.8 million barrels. The result is more precise and reasonable compared with that calculated by the previous method and is easy to further popularize and apply, which takes more factors into account. The new dynamic multi-factor economic limit well pattern density calculation method proposed by this paper can be used to forecast reasonable economic limit well pattern density for all the water drive sandstone reservoirs in China or abroad, which is helpful to realize economic and effective oilfield development.