US oil service company Halliburton Co. will move its headquarters from Dallas to Houston early next year. “Houston is the energy capital of the world and, considering our presence in Houston, it doesn’t make sense to have our corporate headquarters anywhere else,” Halliburton spokeswoman Wendy Hall said. The company did not elaborate on the move’s timing, but said a lease for the company’s headquarters in Dallas expires during the first quarter of 2003. Halliburton already has more than 15,000 employees in Houston. It is the fifth-largest employer in Texas’s largest city. About 20 people who work in the company’s headquarters will move four hours south to Houston, where a number of energy companies, such as ConocoPhillips, have consolidated in recent years.