Challenging Well with Sand Production Risk is Economically Developed Using Oriented Perforation
Authors: Korish M. , El Sayed M. , Moussa A. , Elkhawaga M. 
Published: February 2024

The subject field is located south of Ras Shukier area in the Gulf of Suez offshore the northeastern part of Egypt. The field produces from LR Formation which is one of shallowest in this area +/- 4000 Ft TVD, LR formation is described as weak or unconsolidated sand in this field which is quite unique compared to LR in all analog fields in the Gulf of Suez. Historically the field was produced with cased & perforated completion up to early 1990s where frequency of sand filling increased and several clean outs using coil tubing were required, with the growing number of severe cases when wells ceased to produce due to dramatic sand failure and accumulation covering all perforations. In 1996 two new wells were drilled however the reservoir pressure was measured depleted. Following the same completion strategy of casing and perforation resulted in immediate failure of sand face during unloading, since that date work overs were performed in order to restore productivity of wells and mitigate future sand production adopting sand control completion. The completion strategy then changed to cased hole gravel pack.

The subject well was drilled in 1996 targeting the most up dip location of the reservoir as a part of field development plan, at that time the reservoir pressure was quite low and water injection was not started yet. Which explains the reason the well penetrated a secondary gas cap. Decision of well completion was not straight forward due to the complicated situation, gravel pack completion may restrict put some challenges on future intervention of the well after water injection project starts and gas cap start to collapse, for that reason well was kept Cased & Perforated completion in order to be able to develop the well with bottom up strategy with some flexibility to add perforations above watered out zones and below the developed gas cap. The well-showed sand fill and several coiled tubing clean outs were performed. along with water injection, reservoir pressure increase was observed and time lapse of pulsed neutron logs were taken to monitor progression of water oil contact and gas oil contact as well. A recent cased-hole saturation log was performed and showed gas cap partially collapsed and an oil rim accumulated in an unperforated sand interval bounded by the GOC at the top and higher water saturation zones at the bottom, Sanding study was performed using available sonic data and correlation with offsets showed the proposed interval to be the weakest sand body and would produce sand at any kind of draw down using conventional through tubing perforation.

Exploring the different options for accessing the remaining reserves from the oil rim, the cost and complexity of a workover and gravel pack was quite prohibitive which opened the room for discussing different perforation techniques to allow cheap access of these reserves. A geomechanical evaluation of different perforation options was performed and showed that certain orientations of perforations is more stable than others. Shots that are oriented toward the direction of maximum horizontal stress showed higher stability. Since the minimum horizontal stress component acts as main force on the perforation tunnel, which gives more, roam for perforation stability.

The perforation was performed at optimum orientation of 170 deg Azimuth, and showed 300 BOPD incremental oil production, since the time of perforation and up to date several slickline tagging and sampling were done and confirmed no progress of sand fill over time similarly the surface liquid samples were typically solids free except during unloading.

Oriented Perforation can be economical method for producing wells with sanding risk at lower cost. this option can get wider acceptance using active through tubing perforation orientation tools that can be used to shoot the perforation charges in the most stable direction that maximizes the capacity of the well to be drawdown without sand production or risking the well to be filled with sand.