This article is a synopsis of paper SPE 56527, "New HF Acid System Improves Sandstone-Matrix-Acidizing Success Ratio by 400% Over Conventional Mud-Acid System in Niger Delta Basin," by Nicholas Kume, SPE, BJ Services Co. Nigeria; Robert Van Melsen, SPE, and Luckie Erhahon, SPE, Shell Petroleum Development Co. Nigeria; and Abiodun Afolabi, SPE, BJ Services Co. Nigeria, originally presented at the 1999 SPE Annual Technical Conference and Exhibition, Houston, 3-6 October.