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Electrical Submsersible Pump Powered Injection ESPPI Systems Enable the Development of West of the Nile Egypt Assets

from Volume 38th October 2019

by petroleum today mag

from Volume 38th October 2019, page 40

A Business Case for Environmen...

Technology Applications

Electrical Submsersible Pump Powered Injection ESPPI Systems Enable the Development of West of the Nile Egypt Assets

By: Miguel Munoz and Mohamed Aboutaleb, Qarun Petroleum Company; Jeff Dwiggins, Artificial Lift Solutions Pte Ltd

Abstract

Qarun Petroleum Company (QPC), a joint venture between the Egyptian General Petroleum Corporation (EGPC) and Apache Egypt, operates over 350 ESP wells in brownfields across the Egyptian Western Desert. QPC,s oil production is heavily dependent on the performance of waterfloods and artificial lift systems. In recent years, QPC entered a development campaign in the West of Nile (WON) region, an area located west of the Nile River approximately 159 kilometers from Cairo. The fertile land has ready access to irrigation and therefore long been developed as an agricultural area, surrounded by densely populated villages. Land access is restricted and operations must be conducted to ensure minimal impact to the environment. Oilfield development in WON is challenging and required alternative solutions to conventional waterflood operations. QPC engineers turned to ESP Powered Injection (ESPPI) systems as an alternative to traditional waterflooding and re-engineered the technology to overcome the operational, economic, and environmental challenges. ESP Powered Injection (ESPPI) systems utilize conventional ESPs in combination with a bypass system (Y-tool) and an injection string to provide water production and injection support from a single wellbore to one or more wells in the same injection pattern. The system eliminates the need for surface pumping, water separation, storage, and flow lines. QPC has successfully installed and presently operates nine (9) ESPPI systems in the environmentally sensitive WON region of Egypt. This paper aims to detail the specifications and functionality of ESPPI systems, main challenges and benefits derived from closed monitored installations and operational surveillance, and the economic advantage of its application for QPC.

Introduction

QPC operates the country›s second largest ESP portfolio in the Egyptian Western Desert. The company has over 350 ESP systems running at any given time across nine (9) concessions. QPC is also considered the largest waterflood company in Egypt with 85% of its fields under waterflooding with improved recoveries ranging from 10% to 35%. Fig. 1 shows QPC,s three (3) main areas of operations and waterflooding (Karama, Qarun, and Beni Suef where the WON concession is located). The WON concession, situated approximately 159 kilometers from Cairo, Egypt,s Capital, as illustrated in Fig. 2, formed an important part of QPC,s undeveloped assets. In 2011, QPC initiated a development drilling campaign in the WON after drilling the WON-C01X exploration well and proving commercially. Development plans of WON wells required waterflooding as early as possible in the life of wells to sustain production rates and commercial recoveries. The producing reservoirs were proven to be depletion drive reservoirs primarily. Initial attempts at conventional waterflooding operations proved unsuitable for the development of WON wells.

Agricultural area overlays, limited opened land, and restricted accessed roads presented operational constraints ruling out minimum equipment requirements and operability of surface water injection networks. Dense populated villages and agricultural activities in the area presented high environmental and safety concerns. Natural dump floods, operated by the company on various other fields, came short of meeting water injection pressures and desired target rates. WON reservoirs range from 15 feet to 25 feet on thickness at the injection zone, typically at a depth of 6,600 feet TVD, demanding high injection pressures and costly surface pumping systems to reach desired injection rates.

The ESP Powered Injection (ESPPI) System

ESP Powered Injection technology involves producing and injecting water in the same wellbore through an ESP and a modified by-pass system (Y-Tool) shown on Fig. 3. An ESPPI system is essentially a single wellbore water-source water-injection system. The system uses an ESP and Y-Tool to produce water from a water zone and direct injection to a desired injection zone. In current QPC applications, the ESPPI system produces water from a shallower water-source zone at approximately 6,000 feet and injects the water into a deeper injection zone typically at 6,600 feet. The ESPPI system is a versatile application with configurations easily modified by simple wireline operations. The system can be used as a water-source well for nearby waterfloods serving surface-waterinjection manifolds while fully functioning as a complete water-source water-injection system within the same wellbore. The system can operate in three (3) basic positions or functionalities as described below in Fig. 4. One of the main advantages of the ESPPI system is the elimination of waterflood surface facilities when operated on position B. When the system operates on the B position, the waterflood operation requires no separate water injection well, installation or laying of flow lines, water storage tanks, skimming tanks, or surface pumping systems. The exclusion of the mentioned surface equipment and facilities reduces the footprint of the waterflood operation to a single wellbore and surface Christmas Tree. In addition, field development economics are also greatly reduced from the elimination of a separate water-injection well. In short, the system is considered very «environmentally» friendly while achieving the necessary downhole conditions to allow effective production. Fig. 5 shows a typical WON ESPPI well with no waterflooding surface facilities or flowlines.

QPC ESPPI System

QPC ESP engineering team performed a research of Powered-Waterflood-Injection systems installed and operated worldwide. The study showed that main challenges on system designing were related to low permeability injection zones of less than 10 md, and limited reservoir thickness of the injection zone. Mechanical and operational challenges included jetting effects on down-hole tubulars from high-pressure water source zones and cable damages, long back spinning periods of the pump from charged reservoirs, and extended rig time consumed on equipment make-up and installations. The team worked diligently to address many of these challenges and executed the following modifications: Ó Performed ESP designs taking into consideration the producing-water-source zone and waterinjection zone Ó Selection of mixed-flow wide-range pumps with wider operating ranges to accommodate reservoir behavior changes and demands of future water injection rate adjustments Ó Installation of a locked blanking plug in Y-block rated to 5,000 psi differential pressure to close the Y-tool system loop Ó Setting of the ESP system in 9 5 / 8″ casing to avoid limited clearance of 7″ liners Ó Inclusion in the tail assembly of the following: - VAM TOP Blast joints set against water-source zone and perforations - Self-aligning tool to sting in tail assembly in permanent packer - NU Seal units - Permanent packer to isolate water-source zone from injection zone with UN seal bore extension Ó Use of FJL (Flush Joint Liner) tubing with premium flushed connection threads in bypass tubing for edge-toedge sealing and for higher clearance with the ESP Ó ESP pump selection of 538 series pump, and motors of 562 series Ó Bypass tubing BHA to be pre-assembled prior to arriving at wellsite. Then, make use of torque wrench on rig site for

BHAs assembling to save rig time Ó Real-time surveillance Scada system to be installed on every well for 24 /7 monitoring Ó Limiting the tail assembly weight to 28,000 lbs.

System Developments and Lessons Learned

ESPPI systems became the standard waterflooding method

in QPC WON fields since the installation of the first system in December 2015. The first ESPPI system installed proved successful in the WON C-315 well with an injection rate of 1,200 BWPD. Reservoir pressure was restored to virgin pressure of 2,900 psi in a period of approximately 16 months. Since then, QPC engineers worked on a number of improvements of the technology as field development plans advanced. The ESPPI system installed in the WON C-315 well failed after 177 days with a reported motorshort circuit. A Dismantle Inspection Failure Analysis (DIFA) performed on the system discovered well fluid entry at the motor head with the motor oil smelling burned. During the ESP operating run life, the motor oil temperature measured 245°F while the recommended operating temperature range of the motor was 165°F - 250°F. The motor operated nearest to the upper temperature ranting. The source of well fluid entry was a concern but undetermined. The main corrective action from the subject installation included the use of a higher rating motor oil with an operating temperature range of 210°F - 300°F to avoid similar premature failures. QPC,s second ESPPI installation in February 2016 ran for 649 days. A performance improvement of 472 days of run time. The system was pulled and another one ran in the well with a larger size ESP. The objective of upgrading the size of the ESP was to have the ESPPI system serve as a watersource well to a nearby injector unable to meet its injection target while fully functioning as an ESPPI system in its original wellbore. Subsequent ESPPI installations, including installations in the conversion of three (3) underperforming oil producer wells to water injection wells, have performed to expectations with minor challenges. QPC production engineers experienced problems with the system blanking plug becoming stuck in the nipple above the Y-tool. The situation prevented Production Logging Tools (PLT) operations in the wellbore and the measurement of injection flow rates. To address the problem temporarily, water injection rates and ESP surveillance was conducted via downhole sensor readings and analysis of offset oil producing wells in the same waterflood pattern. As a permanent solution, QPC production and ESP engineers replaced the blanking plug with a Back Pressure Valve (BPV) installed at surface in the Christmas Tree. QPC has completed the installation of nine (9) ESPPI systems in the WON area. Total injection rates add up to 13,300 BWPD per day and approximately 5.2 MM barrels of water injected comulative as of February 2019. Oil production as a result of water injection is estimated at over 4,500 BOPD. Fig. 7 illustrates ESPPI systems installed and under operation by QPC in the WON fields.

Cost Saving Impacts

ESPPI systems have offered QPC important cost savings, both capital and operational, that aid the development of WON fields. All of this has been achieved while being sensitive to environmental conditions. As previously mentioned, ESPPI systems eliminated the need of a separate water-source well and injection wells typically required on conventional waterfloods. Surface facilities are not required including installation and laying of flow lines, tanks, or surface-injection pumps. Main capital costs savings include the following: Ó Drilling and completion of separate water-injection wells and water-source well Ó Purchasing or flowline materials and fittings Ó Purchasing and installations of tanks Ó Purchasing and installations of surface water injection systems The operational cost savings from ESPPI systems are significantly dependent of the application of the system and the company operating philosophy. QPC realized significant operational cost savings in the range of $180,000 - $200,000 per year from an ESPPI system operated on position C (Fig. 4). In future applications, operating cost savings could include, but not be limited to, land rental, other equipment rentals, surveillance system charges, personnel supervision chargers, and power related costs.

Way forward

QPC plans to extend the application of ESPPI systems to other areas of operations and take advantage of the developed in-house experience and field staff familiarity with operating the technology. QPC ESP engineering team plans to work on further modifications of the system to address the challenge of backspinning of the pump. The team plans to try a Variable Speed Drive (VSD) technology featuring a catch spin while running mode. In addition, QPC ESP engineering plans to test other less conventional tools such as TubingDrain Valves (TDV), Auto-Diverter Valves «ADV», and Non-Return Valves «NRV to relief back pressure on the pump after restarting back the system.

Conclusion

As of February 2019, QPC operates nine (9) ESPPI systems averaging 13,300 BWPD of total injection. Production gains as result of the unconventional waterflood operations are estimated at over 4,500 BOPD total for the nine (9) ESPPI systems. By eliminating the requirement of separate wells for water production and injection,

development costs and footprint are greatly reduced. Elimination of surface water handling facilities further reduced costs and environmental impact. The closed loop nature of the ESPPI system also has the advantage of eliminating the hazard of high-pressure surface injection

Figure 1—QPC main areas of production and waterflooding operations

lines, pollution by organic agents, or contamination by surface facilities corrosion. As a result, ESPPI systems made possible the economic development of QPC environmentally sensitive WON fields.