TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe Tangguh LNG gas fields are situated in the Berau Bay, Irian Jaya, Indonesia. An extensive exploration and appraisal program was performed from 1994 to 1998 which resulted in the discovery of 14.4 TCF of proved gas reserves with substantial upside reserve potential. The fields are currently at the development planning stage in support of the Tangguh LNG project, Indonesia's third major LNG center.The objective of this work was to obtain a more accurate skin and non-Darcy coefficient (D) from exploration and appraisal well tests by accounting for completion effects. The impact of corrected D coefficient on well deliverability reduced the number of forecasted development wells.In Tangguh pressure transient analyses, skin and D coefficient from well tests were first calculated based on pressure data from gauge depth. Most of the gauges were placed in gauge carriers integral to the test string and anywhere from 125 to 300 feet above the mid-point of producing interval. Because the pressure drop in the completion from the perforations to the gauge appears as additional skin, the deliverability of the formation could be underestimated if this effect were not considered in the analysis.After the pressure drop in the completion was correctly accounted for, the non-Darcy coefficient decreased in all wells. The D coefficient correction was particularly significant in high transmissibility reservoirs and agreed with theoretical D coefficient calculations. This increased the predicted gas well deliverability.