Production Enhancement by Customised Hydraulic Fracturing Operations: Success Stories of Gamij Field

Abstract

Customized hydraulic fracturing operations in low temperature and shallow reservoirs of Gamij field of western onshore India yielded impressive post frac production gains. This paper describes in detail, the various challenges for hydraulic fracturing in Gamij field, development of fracturing fluid, execution methodology and fracturing’s vital role in production enhancement. Successful hydraulic fracturing operations turned Gamij as one of the promising producing field. Poor reservoir characteristics, thin pay zones, presence of coal layers, shallow depths and low reservoir temperatures were the main challenges for hydraulic fracturing. Numerous lab studies carried out and fracturing fluids were customized for good rheological capabilities and postfrac gel cleanups. Frac job sizes were optimized based on sensitivity analysis carried out using frac simulators. Large size jobs were carried out in suitable candidate wells. Pre and Post frac temperature logs were taken to ascertain the fluid intake and frac confinements. Activation methodologies developed so as to bring the wells on production in minimum time. Hydraulic fracturing jobs in Gamij field were quite successful. Fracturing jobs were carried out in 35 wells in the last two years mostly with drilling rig in position. Most of the wells came on self. Oil production up to 30m3/d in a single well was observed. Job sizes were designed based on reservoir characteristics which ranged from 60000 lb to 242500 lb. 20/40 low strength proppant pumped in these frac jobs with maximum concentration of 15 ppg. Job scheduling varied based on thickness of payzones, behavior of nearby coal layers. Temperature logs showed a good placement of proppant in target zones which helped in getting impressive post frac productions. The results of frac jobs turned this small field into one of the most promising fields in the area. Customized hydraulic fracturing helped in the enhancing the production from ageing & mature western onshore oil fields of India. Success of fracturing campaign in Gamij field led to augmented drilling activity in similar pay zones to extract hydrocarbons and support the increasing energy demand. This strategic hydraulic fracturing methodology customized for other fields in the region which were also proved quite successful.