Development of the computer program to be used in creating flow performance curves and testing it with oil field data

Determination of reservoir pressure profile, bottom-hole pressure, and the relationship between production rate and bottom-hole pressure are very important in petroleum production. The choice of equations used in calculating pressure value at any location from the bottom hole of the well to the reservoir boundary radius, is decided by calculating X value that is used to determine of log approximation. Log approximation holds in case of X<0.01, otherwise, log approximation does not hold. To perform these calculations with computer aid, the exponential integral data must be modeled and the model equations must be derived. In this study, the exponential integral data given in various scientific sources related to petroleum engineering were modeled by using trial version of the Curve Expert Basic 2.2.3 program, and the model equations with high correlation coefficients were developed for different data intervals. Using these developed model equations for -Ei(X), 3 programs were coded in C++ programming language for calculating pressure distribution in the reservoir, single-phase flow performance, and partial two-phase flow performance relationship and tested using Turkey field data. The equations used to derive the reservoir pressure profile include many parameters such as porosity, permeability, boundary pressure, reservoir area and height, formation volume factor, viscosity, and skin factor. Although the effect of each parameter in decreasing or increasing the result is seen in the equations written in terms of parameters, it is not possible directly to decide the effect of variable parameter on the trend of the curve without making any calculation in case of the other parameters are constant. In the section where the reservoir pressure change is determined, the effect of each parameter passing through the equation was investigated in the range of the lower limit value and the upper limit value of Turkey field parameters by using a certain step size. Another computer program was developed in C++ programming language for calculating the relationship between petroleum production rate and bottom hole flow pressure. The effect of each parameter in the inflow performance relationship (IPR) equations was investigated with the help of the prepared program. The calculations made in the study are arranged and presented in a way to gives an idea about production planning for both existing production wells and wells that will be put into production later with similar parameter values. The sample calculations made in this study may be useful in estimating pressure changes in the well and its surroundings with production until a comprehensive geological model is developed, especially in newly discovered oil fields. The developed computer program also provides the opportunity to easily make calculations for new reservoirs and wells by changing the well parameters in the programs.