Production Enhancement in Mature Fields of Assam Arakan Basin by Radial Jet Drilling- A Case Study

Abstract

Abstract Decline of production or premature shut-in of wells due to various problems like reservoir pressure depletion, adverse reservoir characteristics, formation damage (skin) etc. is an increasing problem in the oil and gas production sector. In most of such cases, the remaining resources are likely to be abandoned in view of failure to re-establish the production of the field. Oil India Limited (OIL) has attached a significant thrust on improving recovery from such reservoirs by use of some modern fit-for-purpose technologies. Based on the result of pilot radial jet drilling project, a second campaign has been completed successfully in OIL. The paper represents the operational involvements for the successful completion of the radial jet drilling operations in four (4) nos. of wells (3 oil well & 1 gas well) in four (4) different mature reservoirs of Oil India Limited. The depth of the target reservoirs varied from 2866 m to a record depth of around 3319 m (deepest well in India where radial jet drilling has been implemented). The first well was completed with 4 laterals (length 100 m each) with 90° phasing. The second well had 6 laterals (length 50 m-100 m) with 90° phasing in two different reservoir depths. The third well was completed with 5 laterals (length 10 m- 100 m) while the fourth well was successfully completed with 4 laterals of length 100 m each at targeted reservoir depth. In this paper, the detailed post radial jet drilling production performance of the wells have been discussed and covered. The post job production gain of nearly 800% was obtained. This is the second time; this technique was applied to increase production in the mature fields of OIL, Assam. The technical experience and knowledge gathered from the radial jet drilling campaign certainly confirms that radial jet drilling is a viable alternative to improve or unlock an untapped potential for incremental production for shallow to deep (approx. 3400 m) reservoirs conditions in Oil India Limited as well as in other exploration and production (E&P) operators worldwide.