1. Introduction
     The purpose of this paper is to establish acceptance criteria for interpretation of the inspection results of undersea  pipelines using an internal inspection. Acceptable criteria were established with a case study of a 609.6 mm (24 in.) diameter, concrete weight coated pipeline delivers fuel oil from SPM terminal to the Takoradi thermal power plant, Ghana. The VRA has decided to undertake a pipeline internal inspection. Rontgen Technische Dienst (RTD) will use a special pig to determine out-ofroundness (OOR), presence of dents, reduction in wall thickness, and the x–y–zcoordinates along the length of the pipeline.
2. Relevant pipeline condition
     Several relevant factors relating to the existing pipeline must be considered prior to establishing the ‘acceptance criteria’ for the fuel oil pipeline. Each factor is summarized subsequently.
2.1. Pipeline design parameters
     The pipeline was designed to conform to provisions of the codes and standards (API, 1993; ASME, 1992; DNV, 1981).
2.2. Site conditions
     Environmental conditions at site include a swell ranging up to 1.5 m in height present most of the time. Water depths range from 0 at shore to approximately 19 m at the SPM terminal. A long shore current carries sediment generally in a west to east direction. The pipeline has partially or fully self-buried, either by settlement or by sediment transport, or by a combination of both, over much of its length. Stability enhancing concrete block sets will be installed at selected defined locations alongside the pipeline.
2.3. Pipe characteristics
     The pipe characteristics and physical properties are included in Table 1.
2.4. Installation
     The fuel oil pipeline supplying the power plant near Takoradi, Ghana, was installed in 1997. The first 700 m of pipe were installed by the bottom pull method. Due to installation contractor equipment problems and self-burial of the pipe in the nearshore area, the remaining 3.8 km of pipe was installed by a lay barge. The prefabricated pipe strings stored on the beach were cut into 12-m lengths and transported to the lay barge. A flange connection was made to the end of the 700-m section. Following installation and prior to oil delivery use, in late 1997, the pipeline was successfully hydrostatic tested. Hydrostatic test was undertaken at 18.9 barg (273 psig). The SPM was installed and connected to the PLEM at the offshore end of the pipeline.