Synthesis of Disruptive Technologies Leads to Design of Flowable Sensors for Reservoir Monitoring, Passively Retrievable Through Carrier Buoyancy

Abstract

Technology gaps in measuring wellbore parameters and providing the results at surface without using wireline (Production Logging) or slick-line, without using mud-pulse, electromagnetic or acoustic telemetry, or pre-installed or permanently installed downhole sensors remain an area to be bridged. Our ability to engineer light-weight, high-strength, highly-reactive (dissolvable) or corrosion-resistant, nanostructured-alloys and intelligent micro-electromechanical system (MEMS) devices have enabled design of buoyant sensors having thin (millimetric) wall, capable of withstanding 20,000 psi or more differential pressure. These sensors measure and record a complete set of the client’s required wellbore parameters (e.g., Pressure, Temperature, Depth, Casing collars, Flow-rate across perforations or in wellbore, Water cut, Dissolved O2, etc.). These devices are deployed, either nested in an outer shell of salinity independent water reactive alloy to abet pump down to depth or weighed down by a sinker of dissolvable alloy. These devices are free-flowing within a wellbore so that they can be placed downhole to required depth for a specific time, after which the outer shell dissolves or the sinker weight falls, releasing the inner gauge. The now buoyant device flows back to surface with produced fluids where they make their presence known by sonic or inductive signaling. Our company was founded to take advantage of these disruptive innovations in materials science and sensors and synthesis of these technologies to provide superior performance products for both deep-water domains and the multistage stimulation (MSS) market. In this article we address two of our key inventions. First, the development of miniature, self-contained, battery powered, free-flowing sensor devices for reservoir monitoring, passively retrievable through carrier buoyancy. A subset of this game changing approach, to economize operations is, "Measuring in- situ pressure, temperature, and subsequent production during MSS". Second, we present a mechanism to assess susceptibility of oilfield alloys, especially in live reservoir fluids at the production zone. This encompasses a retrievable sensor device to assess environmental effects on materials at target zone in wellbore during production or shut in, can be deployed anywhere from production zone to bubble point, to surface separator. It facilitates testing not in a simulated autoclave environment at surface, but downhole, at the zone of interest.