Effect of project life time on well placement optimization

Deciding the life cycle of field development projects is one of the problems that routinely face reservoir asset managers. In this work we investigate the effect of production time in well placement optimization as well as the effect of adding well spacing constraints. To make the investigations a synthetic heterogeneous reservoir example was used, and Covariance matrix adaption evolutionary strategy (CMA-ES) coupled with numerical reservoir simulator was used as an optimization tool. The optimization was made on the locations of oil producers and water injectors as well. Two cases were considered; in the first case there were no constraints while minimum well spacing was defined in the second case. To study the effect of production periods in the optimization three classifications were used; short term, medium term and long term, and so short term NPV, medium term NPV and long term NPV set as different objectives functions for each of the mentioned terms respectively. We proved that the optimum well placement for specified project period is not necessarily the best for different period. Adding well spacing constraints to the optimization significantly affected the solution, which shows the importance of selecting the proper minimum well spacing to build fields' development plans.