The HPHT fluid loss control aid also contains a solubilized lignite such as causticized lignite and carbon black. The fluid loss control aid reduces HPHT filtrate loss, has good stability at elevated temperatures such as at 300 °F, stabilizes troublesome shales and decreases bore hole erosion, helps seal depleted sands, reduces torque and drag, causes no adverse effects on the flow properties of the properly conditioned drilling fluid, and lowers total well costs.