Unlocking Unproduced Reservoirs at Existing Gravel Pack Zone Using Straddle Screen: A Success Stories and Lesson Learnt at the Handil Field, Mahakam Block, East Kalimantan, Indonesia

Abstract

Handil Field is a one of field in the Mahakam block which has various types of completion. Gravel Pack Completion is a robust solution to produce shallow reservoirs while also preventing sand from the formation to come out to the wellbore. Occasionally found on gravel pack completion wells, there are several reservoirs on the same Gravel Pack Zone. Due to reservoir properties impairment, not all of these reservoirs can be treated with gravel pack. Therefore, perforation and gravel pack treatment only performed for reservoirs with the highest reserves and also with same reservoir properties. After several years, to increase the production, there is a necessity to unlock unperforated and untreated reservoirs at gravel pack zone to produce the reserves safely. Previous method to unlock these reservoirs is by performing squeeze cementing to isolate previous producing reservoirs; perforation at new reservoirs target and then performing chemical sand control (SCON). This method is considered quite complex, takes a long time; and required high costs. The Straddle Screen is an innovative screen installation, without squeeze cementing, in the hope of producing the existing gravel pack zone in a commingle with the newly opened reservoir in the same zone. Additional perforation in the existing gravel pack zone using straddle screen have been carried out in 6 new reservoirs, in 6 wells in the Handil Field. This paper has the objectives: perform a comparative analysis of operating costs between squeeze cementing versus Straddle Screen installation; and analyze the results of the implementation of the Straddle Screen in Handil Field, Mahakam Block. The procedure begins with collecting well and reservoirs data; determine the type of perforation, type of screen, the installation of the straddle screen; and ends by evaluating the results of the work. Additional perforation work in the compared to the squeeze cementing job with SCON. By the duration, the straddle screens have a duration of only 2 – 3 days, compared to squeeze cementing work with SCON which has a duration of 14 days. From a total of 6 completed works, it was found that the reservoir production succeeded in producing hydrocarbons without any sand. Carrying out direct perforation and install straddle screens has proven to be able to produce even with small stakes, which was previously uneconomical if it had to be done with cementing and SCON operations, especially in existing gravel existing gravel pack zone without squeeze cementing succeeded in opening reserves with a total of 140.000 bbls and 0.08 BCF from 6 reservoirs, and proven has cost saving up to USD 300,000 per job when pack zones.