Determination of Drainage area in naturally fracture reservoir for vertical well

Today with the advances in scientific abilities in predicting the controllable factors in optimizing and success of industrial projects, the need to make a future with simulation and programming in the current important and influential industry in world finance is inevitably felt. With the introduction of the related simulations and software in oil industry, it becomes utterly important to have precise information about what will happen before the digging process including the digging itself, production and reservoir simulation. In this article, prediction of the physical shape of the reservoir, named Drainage area, is discussed. Knowing about the radius of investigation in wells we can find out useful information regarding the boundaries, distribution of pressure in boundaries and the way of direct usage of the basic simulation calculation equation. The history of investigating this parameter goes back to 1960s. With the complementary efforts of Dietz a table was found for the shape of the reservoirs. However, based on the needs of the Persian Gulf countries that our oil reservoirs are placed in formations with natural fracture, calculating this parameter in this reservoir with the use of that table was wrong and will result in unreliable answer. Therefore, we need to calculate this parameter for fractured reservoirs.Generally, in fundamental equation in reservoir engineering, two parameters of CA and A named Shape Factors and Drainage area, entered the equation simultaneously or the equation are defined based on re parameter that gives us the wrong understanding of the boundaries of the reservoirs with the simplification of a cylinder. It worth noticing that the investigation of drainage is possible only if the shape of the reservoir is found. The method of finding CA is using continuous equation of image wells that will not be investigated in this article. Few studies were done on investigating A and CA in NFR. However, the shortcoming of all these articles is using pure mathematical methods and transporting functions for forming fundamental equation or using converging reservoir method for the NFRs. The purpose of this article is calculating A and CA with the help of physical models and using regular experiments on wells to find A and CA. We use IPR curve and well test in parallel.

کلیدواژه ها:

NFR: natural fracture reservoir ، MBH method: Matthews ، C.S ، Browns F and Hazerbroek method ، A: drainage area ، CA: shape factor