Paper: Transient Pressure Interpretation In A Deep Delaware Basin Gas Well

As the search for new gas supplies intensifies, deeper reservoirs are being investigated. The following describes the design, testing, and difficulties encountered in transient pressure analysis in a high pressure, low permeability gas well. The conclusions drawn from the test will also be discussed. Transient pressure testing was selected as the most timely method to describe the reservoir. The pseudo-pressure technique was applied to the data obtained. The subject well, Emma Lou Gas Unit 1, Well No. 1, was completed from 22,156 ft to 22,240 ft in the Puckett West Bend Field, Pecos County, Texas. The initial reservoir pressure was greater than 18,000 psi, and the reservoir temperature was in excess of 360 F. Due to the pressure and temperature in this well being beyond any empirical relationships, the compressibility and viscosity data were obtained from, the Peng Robinson Equation of State. All test data was gathered at the wellhead, and the bottom-hole conditions were calculated from the Cullender and Smith Sandface Pressure Method. Due to a rapid decline in pressure, a multi-rate test was initiated. No conclusive evidence of a reservoir boundary was seen during the testing. However, due to the low kh and deliverability, additional drilling was not undertaken. Even though the test was performed in a limited time and without laboratory analysis of fluid and formation properties, well performance to date has supported the reservoir description from the drawdown and multi-rate tests.