Abstract: A casing safety device and method are disclosed for preventing tools from falling into an open well casing and for venting gases to a distance above the open mouth of the casing. An inflatable bladder is provided for placement in the casing adjacent the open mouth, and the bladder is inflated to block the casing and provide a stop against which falling tools come to rest. Damage to the bladder is prevented by a circular rubber shroud disposed between the bladder and the open mouth of the casing which reduces the velocity of falling objects before they strike the bladder. A vent is also provided for conveying downhole fluids, such as flammable gases, to a distance above the open mouth of the casing.

Abstract: An apparatus and method is disclosed for testing leaks in welds securing a wellhead to a caisson on which the wellhead is mounted without waiting for the welds to cool. The wellhead is placed in co-axial, overlapping relationship around a portion of the caisson on which it is to be mounted to form an annular chamber between the caisson and wellhead. The chamber has an open annular upper junction and an open annular lower junction formed by the overlap between the wellhead and caisson, and a continuous weld is placed along each of these junctions to secure the wellhead to the conduit. Oil is heated to a temperature similar to the temperature of the welds, wellhead and caisson after welding, and this oil is introduced into the chamber before the welds, wellhead and caisson have cooled to test for leaks in the welds.