API RP 79-1 PDF

This document provides guidelines for onshore tripping operations when the well is hydrostatically overbalanced using a fluid column without supplemental surface pressure to control inflow.

This document applies to land drilling operations. Its purpose is to provide information and to recommend practices and procedures for planning, equipment considerations, and execution of tripping operations in overbalanced wells. It is also intended to assist operators, service providers, and drilling contractors in developing their own internal rig-specific procedures for safe tripping operations.