método e aparelho para posicionar a extremidade proximal de uma coluna tubular acima de uma aranha

Method and apparatus for handling a supported tubular string with a string elevator and a spider on a rig to prevent damaging contact between the string elevator and spider while facilitating further connections of add-on tubular segments. The string elevator and supported tubular string descend toward the spider until reaching a predetermined position. The process of setting the spider into engagement of the tubular string is automatically initiated in response to detecting the predetermined position of the string elevator. With the spider set, the string elevator can be unloaded. Optionally, the method may also automatically terminate the string elevator descent in response to detecting that the spider has been set. A preferred apparatus for detecting the position of the elevator includes a tilt switch secured to a fixed position along the length of the Kelly hose.