The discovery of offshore sour and corrosive gas reservoirs and the need to satisfactorily drill and produce them began in the late 1950's. The Ghasha 15 well includes deep oil / gas reservoirs containing up to 38% H2S and 7% of CO2. The objective was to perform safe and efficient drilling and several well testing operations in a highly corrosive environment with a rig that was located in a stand-alone offshore location in Abu Dhabi. The well was an exploration well in a location considered wild or remote well; there was no tower or platform facility with pipe lines to support the well testing operations available. 14 x well drilled previously were unsuccessful in obtaining the necessary reservoir data to prove deliverability. These challenges required the use of state of the art technology and highly reliable down hole equipment to subsequently enable successful exploration & appraisal of future UAE giant gas field development optimization. Among other down hole tools and surface equipment used, highly sophisticated DST tools including HPHT high integrity packer, acoustic wireless telemetry systems, Dual Ported Slick Joints (DPSJ), flanged connections, surface close loop well testing package, special H2S and fire & gas detection systems and dispersion modelling were designed to successfully deliver the required data for field developments. Attention to detail, rigorous planning, team work, multidiscipline input and approach were some of the key success factors in delivering the objectives in a safe and efficient manner. While many drilling, data gathering, surface and down hole tool solutions were employed, this abstract will focus solely on the packer equipment and deliverability

As part of of the studies being done aiming to secure bigger gas and oil resources in the UAE, several fields have been undergoing extensive appraisal & evaluation efforts over the past few years. Starting from a review of seismic, petrophysical and well test data from discovery wells, new appraisal wells have been drilled, logged and tested to refine reservoir models and evaluate static and dynamic reservoir properties. With a focus on determining economic viability, productivity and reserves, well testing is a key source of information, yielding fluid samples, productivity, formation mobility and prodiving key indications about optimal completion options such as well inclination or completion method. To demonstrate the existence of moveable petroleum in a reservoir and/or to provide an indication of the potential productivity of that reservoir, well testing is of particular importance to obtain critical information about undeveloped reservoirs. Well testing provides a full understanding of the attributes of a well so that it can be operated profitably and efficiently. A recently drilled appraisal well includes deep oil / gas reservoirs containing up to 38% of hydrogen Sulfide (H2S) and 7% of carbon dioxide (CO2) was successfully tested using Drill Stem Test (DST) in Abu Dhabi offshore field. In order to successfully appraise this field with its specific nature of reservoir fluids that makes all drilling and data gathering operations extremely challenging, many problems had to be solved in well testing techniques. It had to focus on optimal fluids containment and minimization of release. To achieve those aims, several modifications of the equipment were required. It required extensive risk assement sessions with all service providers and rig contractor, in addition to the real time monitoring of all surface and downhole parametres. A systematic multi discipline planning approach with attention to detail, rigorous planning and team work, were some of the key success factors in delivering the objectives in a safe and efficient manner.