In this paper, we propose heuristic algorithms to solve an original NP-hard load equalization problem in cellular Heterogeneous Networks (HetNets). Primarily, we suggest a user association scheme applying dynamic cell range expansion (DCRE) for small cells, where a dynamic power offset is optimized and used to enhance their coverage area and thus improve network load balancing. Thereafter, we introduce a second user association scheme called fairness gain based load equalization (FGBLE), where selection of mobile users (MUs) is based on the measured MUs' fairness gain. Simulation results show that proposed user association frameworks lead to significantly better load balancing, more efficient mitigation of cell overload and more equitable distribution of users compared with the Best-SINR and Fixed offset based load equalization techniques.