Abstract
This article presents the development of laboratory tests and workflow methodologies at Pemex E&P to identify the type and mechanism of formation damage arising during the production life of oil and gas wells in carbonate and sand formations. More than 130 workflow procedures were designed and developed for matrix stimulation and fracturing treatments at Pemex E&P from 2006-2012 and, as a result, a 413% production increase was achieved, highlighting the importance of developing the TIDP (Tests to Identify Damage Type) laboratory test methodology, which may be applied throughout the life cycle of a well. To test the methodology, it was first applied to 100 fluid samples taken at the surface and at the bottom hole of oil wells in which the productivity had decreased, with the following results: 75% of the damage was from stable emulsions formed by oil, water and solids, 20% was from organic deposits, and 5% from inorganic deposits. The TIDP methodology was also applied to completion wells, analyzing 50 fluid samples taken mainly at the bottom hole, and indicated that 85% of the damage was a result of mud emulsion + solids + brine + well fluids, 10% resulted from mud emulsion + solids + well fluids, and 5% from mud emulsion + well fluids. Once the damage types and location in the reservoir and well production system were identified, 40 candidate wells were selected and treatment types were determined, depending on the laboratory test results and the formation type. From these 40 wells, it was concluded that through the identification of the damage types and mechanisms that were obtained with the methodology, it was possible in the short term to achieve 30-400% production increases in these wells and economic benefits of more than $2 million USD per day.
