APPARATUS AND METHODS FOR SEALING AROUND THE OPENING TO AN UNDERGROUND BOREHOLE
摘要
<p>Apparatus useful for providing a liquid-tight seal around an opening formed in the earth's surface of an underground borehole includes a clamp and at least one platform. The clamp is configured to engage a wall extending around the borehole and the platform is configured to extend outwardly from the clamp over the earth's surface adjacent to the borehole.</p>
