A New Approach for Productivity Enhancement in Mature Sand Prone Fields Having Nearby Water Contact Through Slick Water FracPack: A Case Study

Abstract

Abstract Due to nearby water contact, conventionally cased hole gravel pack (CHGP) was preferred completion techniques for sand prone reservoirs in western onshore basin and KG basin of India. However, these completions had often performed poorly both in terms of productivity and longevity. This paper describes the detailed case studies for new completion approach (i.e. Slick Water Frac Packing) adopted to alleviate the productivity decline including favourable modification in completion procedure & job treatment. Since inception, Cased-hole Frac Packing (CHFP) was avoided owing to incompetent shale barriers and nearby water contact. Later on, Horizontal Open-hole gravel packing and Standalone screen completion techniques were adopted but result was not encouraging. The productivity decline was further aggravated with "water-shut off" treatment prior to cased-hole gravel packing. The existing completion strategy was reviewed to identify the shortcomings & a new completion strategy of Slick Water Frac packing(SWFP) adopted for these fields, which was further customized to suit the specific well conditions. When these customized SWFP were implemented, significant improvement in well performance was seen, in form of hydrocarbon production. Till date more than thirty wells have been completed with SWFP. Among them, many wells were already producing water beyond the acceptable limit while some wells have very near water contact (< 2.5 m) without competent barriers. Apart from this, one well had long history of fines production and CHGP / standalone screen (SAS) completion applied did not give good result. The execution of customized SWFP was successful in almost all wells and amount of proppant placed in the formation was the range of 300-1000 lbm /feet of perforation. These completions have achieved the objective of productivity enhancement with average incremental oil gain of about 22 barrel per well apart from formation sand retention. Although some SPE papers have described the CHFP application in wells having near water contact, but the combination of WSO treatment and Frac packing treatment for wells already producing high water cut, is unprecedented as per author's knowledge. The information provided in this paper can be used to enhance hydrocarbon production without increasing significant water production in similar fields.