Nanofluid Coreflood Experiments in the ARAB-D

Abstract

Abstract This paper addresses a critical step on the road to having in-situ reservoir agents. It targets the limiting size of these devices and endeavors to model their transport mechanisms in the rock matrix. It also details an experimental study on nanofluid coreflood experiments in the ARAB-D formation of the giant Ghawar field in Saudi Arabia. The study aims to test the feasibility and future reality for displacing molecular nanoagents in the reservoir. The testing objectives, process, and results are further detailed herein. Introduction The initiative for deploying nanoagents in the reservoir is part of an umbrella initiative for in-situ sensing and intervention (ISSI) at Saudi Aramco. The ISSI focus area works at identifying and developing enabling micro-nano-technologies (MNT) in support of the company's upstream E&P (i.e. exploration, drilling, production, and reservoir) operations. Logically, having in-reservoir nanodevices will require first and foremost determining the maximum usable size of these devices before attempting to develop interrogatable (passive) nanosensors or steerable (active) nanomachines. And this critical step has its own roadmap that involves [1]:making an assessment of the rock's pore throat size distribution to establish a first rough estimate on a usable size or size range for these agents,acquire or formulate stable, uniform, and inert nanoparticle suspensions with narrow distributions of different particle sizes, andconduct coreflood experiments to validate the particles stability and their transport continuity under realistic conditions. The paper is concerned with the coreflood testing that intends to identify and understand the needs to implement the idea in the field. Conceptually, nanofluid coreflooding is rather simple. It involves injecting a slug (about one tenth of a pore volume or 1 cc) of a well characterized nanofluid solution at one end of a core sample and follow this with continuous injection of ultra-filtered particle-free water. The effluent fluid at the other end of the core is then monitored and characterized for its content in nanoparticles. As such, it is hoped to formulate an idea on the transport potential of these particles within the rock matrix. In the particle concentration versus injected volume plot, the influent response is a Heaviside type function and the effluent response is generally a skewed bell-shaped function.