This paper discusses a new generation of inflow control devices (ICDs), which are known as autonomous inflow control devices (AICDs) that can balance production flow and restrict the unwanted fluid. This paper describes the functional testing conducted to evaluate the performance of the fluidic diode type AICD for oil conditions of less than or equal to 1.5 cP and the restriction of unwanted gas in field-like conditions. It will also compare flow performance curves to those of a traditional nozzle-type ICD. Unbalanced inflow from a reservoir can result in water or gas breakthrough, and unless this situation can be addressed satisfactorily, valuable reserves may be lost. When oil is producing from all zones, the AICD will behave as a passive ICD, thereby balancing flow. However, when lower-viscosity fluids break through, the AICD provides a choking effect, significantly reducing flow from the zone responsible for producing these undesirable fluids. Such autonomous characteristics enable a higher recovery rate of oil and also reduce the cost for processing the unwanted fluids. The AICD creates this change in production performance without control lines, moving parts, or electronics. The AICD presented in this paper, also known as Range 1, has an innovative fluidic sensor that is highly sensitive to the fluid properties and is currently best suited for oil viscosities of 0.3–1.5 cP. The Range 1 AICD uses an autonomous on/off type switching function upon gas breakthrough to control gas inflow instead of a gradual change in total flow performance as provided by other inflow control device types. Oil flow is fed directly to the exit port of the AICD, while gas is "switched" to a highly restrictive, spinning path that limits gas production through the tool. Results from single-phase experimental flow testing with oil and nitrogen are presented and discussed. The test results demonstrate that the AICD is an effective tool for restricting gas production. The discussion further shows that if technology, such as the new AICD, is applied to a well-completion design, total oil recovery can be enhanced by increasing the life of the well and reducing the production of undesirable fluids.

Multilateral completions are vital in the oilfield development of thin-layered reservoirs by enhancing field economics and oil productivity through improved reservoir exposure while reducing operating costs. Gas and water coning in thin oil columns can compromise production longevity. The first successful subsea implementation of dual-lateral infill horizontal wells completed with autonomous inflow control devices (AICDs) is discussed. The reservoir is located in an offshore field in the North West Shelf, Australia, and includes a thin oil rim with gas and water breakthrough challenges. Long horizontal wells are typically completed as open hole with standalone screens (SAS) or gravel packs, which can create nonuniform reservoir influx along the wellbore. Water or gas coning can cause uneven reservoir drainage that can result in valuable bypassed oil being left in the reservoir. Advanced well architecture using multilateral horizontal wells with AICDs has been used to extend production life while also reducing production costs and handling and treating unwanted fluid. Technical Advancement of Multilaterals (TAML) Level 5 dual-lateral AICD completion design considerations along with the implementation methodology and well flow performance with AICD completion are discussed. The primary objective when designing these infill wells was to access bypassed oil. Two dual-lateral horizontal wells were successfully drilled with a total reservoir length of approximately 10 km. Both of the sandface completions were enhanced with the deployment of fluidic diode AICDs and swellable isolation packers placed along the main bore and lateral to create a uniform drawdown while also limiting both gas and water production sourced from an existing gas cap and water aquifer. The first case study in the offshore field in Australia where advanced completion techniques were used in combination with a TAML Level 5 dual-lateral AICD completion to maximize reservoir exposure, enhance oil production, and control gas/water breakthrough to increase oil recovery is discussed.

Applying proven technology to control the production of water and gas has become necessary to extend the life of very light-oil reservoirs while optimizing economics. Traditional inflow control devices (ICDs) can help balance the flow of oil, but are not helpful once water and gas breakthrough occurs. Multiphase data and field-evaluation applications show that low-viscosity, fluidic-diode, autonomous ICDs (AICDs) support the production of very light oil while restricting gas and water. Testing has proven that the low-viscosity, fluidic-diode AICD can differentiate oil from water and gas, even very light oils. Tool performance was characterized by measuring the pressure differential vs. the flow rate of diverse oil viscosities representing very light-oil formations in Canada, Russia, Malaysia, and Brazil. The AICD was flow tested with very light oils, water, and gas, as well as multiphase testing simulating mixtures of oil/water for different water cuts and oil/gas at diverse gas-volume fractions. The characterization of flow performance was embedded into sophisticated reservoir simulators for steady and transient evaluations. The multiphase condition of the test fluids was achieved by increasing water cuts and gas-volume fractions. The flow performance tests indicated that the highly sensitive fluidic sensor of the low-viscosity AICD enhances the production of very light oil and restricts water and gas as the water cut and gas-volume fraction increase. The restriction process gradually increases as per the water and gas ratio in the mixture and is reversible if water and gas production recede. Comparisons of the low-viscosity, fluidic-diode AICD vs. a traditional ICD show approximately 25% less water production and 40% less gas production with the AICD. The ability of the low-viscosity AICD to produce very light oils while restricting the flow of gas and water extends the life of light-oil reservoirs by increasing the production of hydrocarbons while helping to lower costs. For optimum reliability, this unique fluidic-sensor technology has no moving parts or control lines, but uses fluid dynamics to distinguish fluids. Multiphase-flow performance testing and field simulation of light-oil reservoirs indicate that the low-viscosity, fluidic-diode AICD favors the production of light oil (0.3 cP–1.5 cP) and restricts the flow of gas and/or water in a multiphase production-flow environment.

Inflow control device (ICD) technology helps in balancing the production across the entire interval, addressing some of the challenges associated with horizontal and deviated wells. Nevertheless, ICDs have limited capabilities in identifying and restricting unwanted fluids upon breakthrough. Autonomous ICD (AICD) technology functions similar to an ICD initially (i.e., balancing flux across the length of horizontal wells, effectively delaying breakthrough) but has the additional benefit of restricting the flow of unwanted fluids upon breakthrough. Multiple AICD case histories highlighting the benefit of the technology in mitigating well performance challenges and delivering improved recovery throughout the life of the well are discussed. AICD technology is fluid dependent, principally reacting to the properties of the fluid flowing through it and creating an additional pressure drop to restrict the production of unwanted fluids. The fluidic diode-type AICD has no moving parts and uses flow dynamic properties to distinguish between the fluids. It uses downhole fluid properties to accurately differentiate between oil, water, and gas; and changes the flow path autonomously to restrict unwanted fluids upon breakthrough; and uplifts oil production from the oil-saturated zones across the wellbore. Extensive testing has been completed to characterize and accurately predict the flow performance, which enables designing an AICD completion efficiently. Flow performance analysis of the various types of fluidic diode AICDs designed to address various well performance challenges [i.e., high gas-oil ratio (GOR) or high water production or both, increasing oil production] is discussed. The flow performance analysis has been derived using extensive and rigorous single-phase and multiphase flow-loop test programs, covering the wide range of oil properties. This paper will also highlight the screening criteria in selecting a candidate well for fluidic diode AICDs application. Furthermore, the paper will also discuss in detail a reservoir-focused well-centric completion design workflow for designing fluidic diode-type AICD completions for a candidate well. This collaborative workflow takes into account the various subsurface and well attributes to meet or exceed well key performance indicators (KPIs) over the life of the well. It can be observed from the results of various field installations and production data analysis that installing AICDs during the early life of wells or fields results in a higher ultimate recovery (UR) compared to installing it in brown or matured fields. However, the recovery with AICD in brown/matured fields can be higher than ICD or any other legacy openhole completion. The fluidic diode AICD design methodology and field installation results for AICD technology in different completion designs, such as openhole gravel pack, open hole, retrofit, artificial lift completion, and multilateral wells, are discussed as well. Additionally, it will also discuss the entire cycle—from flow-loop testing, candidate well selection, pre- and post-drilling AICD well modeling and design, calibration, and post-installation well performance reviews for an efficient and valid evaluation of the technology.

Light-oil reservoirs are affected by the undesired production of water and gas. After breakthrough, these undesired fluids decrease the life of the well, leaving valuable reserves downhole. Inflow control devices (ICDs) delay the production of these undesired fluids; however, they become ineffective after water and gas production begins. Multiphase data and production installation history show how the Autonomous ICD (AICD) with fluidic dynamic technology favors the production of light oil while restricting gas and water. The fluidic diode AICD completions have been successfully installed since 2011 in carbonate, sandstone reservoirs, as well as standalone screens and gravel pack completions. The fluidic diode AICD responds to changing well conditions with no action from the operator. When water and/or gas reach the wellbore, the AICD changes (with no moving parts) the flow path of the fluid and restricts its production. The flow through the device has been validated with extensive testing for single-phase oil, water, and gas. To characterize its performance with the mixture of oil and undesired fluids, multiphase testing has been performed simulating various water cuts (WCs) and gas volume fractions (GVFs). The AICD was characterized by measuring the pressure drop vs. the flow rate at various oil viscosities that represent the light-oil formations in the Middle East. The WC and GVF of the test fluids were altered by increasing the water and gas ratio. This ratio increase enables representative testing of downhole conditions for Middle East reservoirs. The flow performance tests show that the fluidic diode AICD enhances the production of light oil and restricts water and gas as the ratio in the mixture of the undesired fluid increases. When comparing the AICD to a traditional ICD, the AICD exhibits at least 40% more flow of oil than water and approximately 50% less production of gas. Reduced water and gas flow helps reduce operating costs and represents more revenue from the oil production as a result of extending the life of the well. The fluidic diode AICD is a reliable solution to increase the ultimate recovery with no intervention or moving parts. It has been proven that it can promote hydrocarbon production and restrict the production of gas and/or water. The AICD flow performance is predictable in single and multiphase flow. The fluidic diode AICD has been successfully installed in light-oil reservoirs in the Middle East and the North Sea.