Successful First Multistage Hydrajet Assisted Fracturing Process in an Ecuadorian Mature Field

Abstract

Abstract This case history paper presents the first multistage fracture stimulation of a mature field well in Ecuador using a hydraulic workover unit deploying jointed pipe. The process used a hydrajet perforating application followed by tubing-path pumping of the fracturing treatments. To place fractures properly in each pay zone, effective diversion is required. This has been a challenge in many fields of Ecuador. Furthermore, multistage fracturing completions have represented a complex process when applying conventional methods because of the number of operations involved, such as perforating, fracturing, setting isolation plugs, and cleaning out the wellbore for each interval. Several trips into the well are often required, which adds time and costs to the entire completion intervention. Because of the absence of some information as well as the presence of upper open perforated intervals, the hydrajet assisted fracturing (HJAF) process, which uses highly effective abrasive jet perforating immediately before the fracturing stage, was used to provide a degree of flexibility for making additional decisions and performing changes during the operation. This paper presents the detailed workover planning, multiple customized fracturing designs, operations data, and the stimulation results of the case study. The multistage hydraulic fracturing technique was designed and applied to individually fracture stimulate three formation layers in the Ecuador mature field. The method allowed using customized treatments for each zone and more aggressive fracturing schedules to promote high fracture conductivity or length when necessary. Successful production from the mature Ecuadorian field was achieved using the multistage hydraulic fracturing HJAF method. Additionally, this method does not require mechanical zonal isolation between stages. The HJAF technique provides an attractive option for applications in similar wells to help recover additional reserves.