This paper describes the implementation of an expandable system to shut off gas production from a 6 in. open-hole section. The paper will investigate the gas production problem, proposed methods of solutions, advantages of the expandable system over other methods and the deployment of the system to shut off the gas production.
The subject field of this paper is Ashrafi Field located in the southern Gulf of Suez in Egypt. The field belongs to Agiba Petroleum Company, which is a joint venture between IEOC (a subsidiary of ENI) and the Egyptian General Petroleum Cooperation. It is a mature field with a depleted weak water aquifer reservoir and a secondary gas cap at the top of the hydrocarbon column. The expandable deployment in this well is the first deployment of its type in the Middle East.
The expandable system used included a 6.015 in. expandable liner hanger, 4-3/4 in. expandable base pipe, 7 expandable open- hole/cased hole packers* (Fig. 1) and the first-ever deployed worldwide one-trip 4-3/4 in. shoe to drift the system post expansion in one trip. The total length of the expandable liner is 582 feet.
Fig. 1: Expandable Packer (Available in full paper)
The gas shutoff study took two months. A comparison between alternative methods of shut off different techniques, shipping and preparation of equipment took three weeks and the job was performed in 24 hours, including 5.5 hours of making up the system 13.5 hours of RIH and 5 hours of expansion. The running tool was pulled out safely after the job and the well is currently producing with less than 0.7 MMSCF/Day gas and 2700 BOPD with a gain of more than 1600 BOPD* and drop of 14 MMSCF/Day in gas production.
The system is considered to be a milestone in such applications, and more operator companies are considering it at the moment because it will:
Ensure effective results.
Allow more well intervention in the future.
Can be deployed in any formation regardless of its type and regardless of the well deviation.
Ashrafi field is an offshore field located in the southern part of the Gulf of Suez of Egypt, 66 Kms to the north of Hurghada town and 4 Kms. to the east of Ashrafi island (Fig. 2).
Fig. 2: Location Map (Available in full paper)
It is characterized by complex set of tilted normal fault blocks of Pre-Miocene age (pre-rift) covered by a thin (syn-rift) section. Two main fault systems are present: the 'Clysmic' rift trend oriented 'NW-SE' represented by down-throwing normal faults with dip ranging from 40 to 65 degrees and the cross system oriented 'ENE-WSW' (N80-N110 degree), which behaves as a transfer element.
The field includes two major blocks (Main field and Southwest field) that are currently producing about 17M Bopd. The blocks are tilted according to the regional dipping of the southern part of Gulf of Suez towards the southwest, with the main up-dip leading fault to the east. The main bearing and producing zones are Nubia sandstone and fractured granite Basement as shown in (Fig. 3).
