Perforation Strategy for Sand Management in Lower Fars Unconsolidated Formation Presented by: Amr Zeidan Heavy Oil Group

Outlines Objective Approach used in the study Conclusion of Laboratory test Well modeling on Perforation sensitivities Performance comparisons and ranking Findings and analysis Completion with and without Sand Control Recommendations and way forward Q&A

Objective To develop a perforation strategy for Lower Fars formation in 60 MBOPD Project phase-1 based on the learning from NLSTP (North Large Scale Thermal Project)

Approach used in the study Laboratory Test Well Modeling Actual Field Data

Conclusions of laboratory tests Whole core samples taken from shallow oily sands can be effectively recovered and used for large-scale perforation and flow testing applications. Perforation penetration depth is adequate in the subject sands, and attention should focus on the hole size in the cement and casing. Based on laboratory results, steam stimulating SR field will result in enhanced production because of the favorable response displayed by the viscous oil when heated. Maintaining pressure in the wellbore over 200 psi higher than the pore pressure during perforating will help mitigate plugging of the casing caused by the small DUB (Dynamic Underbalance) effect during the perforating event. Relatively smaller holes, approximately 0.235 in. in diameter, in the casing at approximately 4 SPF are feasible during the CSS cycles to ensure a uniform steam injection profile, as well as provide for a sufficient surface flow area when the well is turned over for the production phase of the cycle.

Prosper Model with Sensitivity to Shot Densities (SPF) IPR (inflow performance relationship Pressure vs Liquid rate is generated by Prosper model to evaluate the performance of the inflow from the reservoir at different current perforation densities. The higher the shoot density the higher the AOF (absolute open flow). AOF by definition is a theoretical value indicated the maximum liquid rate when the Pwf (Bottom hole flowing pressure equal zero

Prosper Model with Sensitivity to perforation Entrance Hole Diameter (EHD) The bigger the entrance hole diameter of the perforation charge, the higher the AOF (absolute open flow).

Different combination sensitivities Different combination of SPF and EH then the current ones can give higher AOF (absolute open flow) for example 6 SPF and 0.38” EH

Perforation System Selection Perforation selection role in production optimization Considerations for selecting best perforation strategy Nature of formation and level of consolidation Type of production and/or EOR Number of wells to be perforated Basis of selection (Laboratory work, well modeling, and actual field data) Well model compares production rate VS. Different EHD and SPF

Actual Field Data Three types of perforation were considered to evaluate the performance of those wells Evaluation based on their performance about sand production and normalized total production rate A number of wells from the CSS pilot were selected with the following perforation parameters: 6 SPF, 0.24” EHD 9 SPF, 0.38” EHD 12 SPF, 0.8” EHD Two of those wells were subjected to steam injection from the first day as they are dedicated injector in the coming phase of SF (SR-136 and SR-118)

Sand accumulation in wellbore Sand production plugs artificial pump and defer production Sand production can cover perforation intervals and cease production How to manage sand production by selecting appropriate perforation strategy??

Wells’ sand and liquid rates ranking

Comparison results for cold production Wells perforated with small perforations EHD 0.25” had less sand production based on the height of sand measured during well interventions but lowest production rate Small EHD created critical drawdown which managed the sand production (in agreement laboratory work recommendations). Wells perforated with 0.38” EHD had a medium sand accumulation but best production rate BH 0.8” EHD had the worst sand production and moderate production rate. Further analysis and evaluation of the study focused on comparing 0.25” and 0.38” EHD wells. Due to mixed results of wells received steam from the beginning , further analysis carried out for hot production for fair comparison

Hot Production comparison based on normalized average Rate Comparison of normalized average rate between cold and hot production

Completion with and without Stand Alone Screen

Sand control completion Number of stand alone screens (SAS) installed in NLSTP wells to evaluate well performance under sand control completion. Evaluation is ongoing. 5 Acre: SR-143 SR-128 10 Acre: SR-110 SR132

Conclusions The performance of 6 SPF, 0.24” EHD outperformed the 9 SPF, 0.38” EHD from sand production perspective during cold production but showed less production rate. The performance of 9 SPF, 0.38” EHD outperformed 6 SPF, 0.25” EHD during hot production from liquid rate perspective and showed mixed results for sand production during cold production period. Decision for perforation is based on the development strategy of the commercial project where the majority of the wells will be steamed from day one. The conclusion is to perforate all the wells in the commercial project with 9 SPF, 0.38” EHD.

Q&A Thank You