New Intelligent Completion System Enables Compartment-Level Control in Multilateral Wells

TECHNOLOGY UPDATE

Stephen Dyer, SPE, Schlumberger, and Brett Bouldin, SPE, Saudi Aramco

Although early inflow control devices tight formations and a shortage of suit- ration and Petroleum Engineering Cen- and intelligent completions (ICs) were able surface locations drove the need to ter Advanced Research Center issued an introduced almost 20 years ago, comple- dramatically increase reservoir contact industry challenge in 2007 requesting tion technology has not kept pace with per wellhead. an extreme reservoir contact (ERC) well advancements in drilling technology. Before 2007, the company had suc- containing 50 to 100 intelligent later- Today, wells completed in multilay- cessfully drilled and completed a num- als to efficiently drain the reservoir and ered reservoirs, multilaterals with com- ber of multilateral ERD wells, achieving ultimately maximize economic recovery. partments of varying pressure, and more than 5 km (16,400 ft) of reservoir The company’s goal since then has been extended-reach drilling (ERD) with well- contact per well. These maximum reser- to increase average reservoir contact to bores as long as 12 km are becoming com- voir contact (MRC) wells were completed approximately 10 km (32,800 ft). mon. In complex, hard-to-reach reservoirs with then state-of-the-art IC technolo- and tighter formations, operators need to gy. Completions consisted of permanent Next-Generation Technologies maximize reservoir contact in every well downhole gauges (PDGs) and downhole Saudi Aramco embarked on an 8-year col- to optimize reservoir drainage and mini- flow-control valves (FCVs), which could laboration with Schlumberger to develop mize costs. Yet the evolution of ICs has be partially or fully opened or closed by next-generation IC technologies. The pri- lagged, creating a technology gap with sig- hydraulic control lines from the surface. mary objective was to replace multiple nificant ramifications. Monitoring and control stations were hydraulic and electric control lines with IC reliability has been steadily increas- installed in the motherbore above the one electric control line that could power ing over the years, reaching more than junction to each side lateral. a theoretically unlimited number of intel- 97% for the life of the well in many While IC systems provided distinct im- ligent laterals. The result, commercial- applications. Most permanent downhole provements, three challenges remained. ized in September 2015, is the Manara monitoring and control solutions still 1) PDGs monitored only pressure production and reservoir management consist of a separate “kit” of products and temperature, and these system (Fig. 1). rather than an integrated system. measurements came from an entire The modular system is the industry’s Traditional IC systems lack sufficient lateral or well, not from individual first IC platform to enable simultaneous, real-time measurements in individual zones within each lateral. Thus, real-time monitoring and control of up producing zones to facilitate “cause and there was insufficient information to 60 compartments in multilateral wells effect” decision making. Without detailed to fully diagnose zonal issues or extended-reach sections longer than compartmental information and control without resorting to traditional 12 km (39,370 ft), using a single electric in case of water or gas breakthrough, costly and time-consuming control line. operators are forced to restrict produc- interventions. The system minimizes connection tion, intervene, and in some instances 2) The need to install a separate points and splices, simplifying installa- work over the entire well. control line from the wellhead tion and enhancing reliability. Compact Until recently, there has been no way to every hydraulically activated stations integrate an infinitely adjustable to maintain production from other unaf- FCV imposed an upper limit on FCV with sensors that measure water fected zones during the long diagnostic the number of ICs in each MRC cut and fluid flow rate, as well as tradi- process of production logging, well test- well. Only three or four controlled tional pressure and temperature, in real ing, interpretation, and execution of an laterals were feasible. time. The backbone to this innovative appropriate well intervention. The typi- 3) There was no ability to get power ERC solution is a set of robust, patented cal optimization cycle substantially rais- and telemetry into multilateral inductive couplers integrated into the es operating costs while delaying vital branches and allow effective zonal casing or tubing, providing bidirectional production for weeks or months. monitoring and control. power and telemetry between the upper Consider Saudi Aramco’s experience Saudi Aramco’s vision was more ambi- and lower completion stages and across with ICs in remote oil fields, where tious than that. The company’s Explo- any number of lateral junctions.

18 JPT • SEPTEMBER 2016 Fig. 1—The new electric production and reservoir management system for the first time provides downhole permanent monitoring and in-lateral flow control of multiple zones and compartments in real time—including in multilateral wells. Source: Schlumberger.

By decoupling upper and lower com- Other compartments in front of or Electronics were tested with more pletion stages, engineers can now reli- behind the problem compartment can than 12,000 impact shocks at 250g, and ably deploy the lower completion to any continue producing uninterrupted. Addi- ICs were subjected to horizontal drill- target depth by means of drillpipe, with- tional logging and well testing are no ing shocks at 210 rev/min for 100,000 out fear of damaging the electric umbili- longer necessary to allocate production revolutions. The variable choke on the cal. This “two trip” method minimizes or identify, isolate, and rectify the source FCV survived high-pressure erosion tests the risk of running completions in very of problems. including 40 tons of sand. long horizontal wells. To enable production engineers to Such extensive testing was a minimum The upper completion is connected integrate, analyze, and act decisively on requirement to field a permanent elec- through an inductive coupler, which has a high volumes of real-time surveillance trical system in the harsh environment robust, debris-tolerant stab-in connector data from multiple laterals and compart- where its use was planned. that requires no orientation or rotation. ments, a new intelligent software inter- Stages can be connected and disconnected face was developed, which is fully com- Shaybah Oil Field Case Study as often as necessary, simplifying upper patible with existing data infrastructures, After years of development, testing, and completion workovers. For example, an provides automated well performance refinement, the first fully electric IC sys- electrical submersible pump or safety status, updates reservoir and production tem was installed in two wells in the valve can be replaced without having to models, and recommends adjustments to Shaybah oil field of the Rub’ al-Khali pull the lower completion. This inductive continuously optimize recovery. Work- desert, 800 km southeast of Dhahran, coupling connector system is inherently flows that previously consumed weeks or Saudi Arabia, during 2015. The field is more reliable than wet connectors. months can now be completed in a day. surrounded by mountainous semicircu- Integrated monitoring and control sta- The all-electric system was jointly lar sand dunes as high as 200 m (656 ft). tions can be installed in each lateral or developed by more than 190 research Multilateral wells are distributed across well section, and sensors placed before and engineering experts from Saudi the oil rim between a large gas cap and the FCV analyze the production char- Aramco and Schlumberger. Two hundred the underlying aquifer. acteristics of each compartment before fifty man-years were invested in research The conventional IC configuration commingling in the tubing. When water and development. More than 525 tests for a trilateral well consisted of a dual or gas is detected in a compartment, the were performed to verify reliability and pressure and temperature gauge for the FCV can be choked or closed to minimize integrity, some as short as hours and entire well, with three downhole FCVs undesirable fluid production. others lasting more than a year. and four mechanical control lines. The

20 JPT • SEPTEMBER 2016 metric PDGs in the well tubing. Adjust- ments were made to correct the condition and balance production from each compartment of the lateral at very differ- Station Coupler Single cable ent drawdowns. Had this been a single conventional lat- One control line Water cut eral, the tight area would have produced Flow rate Pressure almost nothing, but the additional com- Coupler Temperature partments and fine flow control enabled Pressure Temperature different compartment drawdowns in the same lateral. The production could still Sandface measurement and control be balanced even though the compartment permeabilities were different. Fig. 2—The world’s first fully electric intelligent completion system was installed in Saudi Aramco’s Shaybah oil field, in a trilateral well with 6 km The well was then optimized to give of reservoir contact. Source: Schlumberger. uniform influx (flow per unit length) for all six compartments. Using the variable orifice FCV and the venturi flowmeter, conventional FCVs were run with pack- mance on the fly. No predictive or inter- each compartment was simultaneously ers in the motherbore, and flow control pretive models are needed. All that is adjusted to a target flow rate by tweaking was only possible for a whole lateral. required is to start “driving” the system: the orifice settings and watching results Instead, six integrated measurement and make changes, observe the response, and until everything was on spec. This was control stations were run, two in each make further changes until the desired a remarkably intuitive approach to well lateral, powered by four inductive cou- optimization is realized. flow allocation, which required no work- plers and a single electric control line The fast-response iterative method by flows or predictive modeling. It was only (Fig. 2) for a modest 6 km of total reser- which the system is used is very natural necessary to drive the system until the voir contact. to the way that humans think, and makes desired results were achieved. The system’s hardware and software it easy to operate. New personnel can run To date, the industry-first system has successfully demonstrated that an oper- the system successfully with a few min- been installed in four wells. It allows ator can optimize well production rates utes of training. operators to access untapped reserves zone by zone using a “cause and effect” This style of control and sensing at extreme distances with existing facili- methodology. This is different from con- showed promise very early. During the ties and develop fields with fewer wells. ventional hydraulically controlled ICs, initial flowback, a high drawdown con- The system enables operators to imme- where reaction times are slow and per- dition occurred on one low-permeability diately identify problematic zones, formance data are limited. compartment, which caused free gas diagnose the cause, and rapidly adjust By analogy, fine flow control is the to develop. The condition was quick- downhole valves to keep wells on pro- “hands” and quick sensors are the “eyes.” ly detected by three separate systems: duction, which reduces capital and oper- The new technology means there now is a drawdown pressure monitoring, the ating expenses while increasing return simple system for optimizing well perfor- system’s permittivity sensor, and gravi- on investment. JPT

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