A New Formation Wettability Test: The Dynamic Wilhelmy Plate Wettability Technique

Abstract

A New Formation Wettability Test: The Dynamic Wilhelmy Plate Wettability Technique M.A. Andersen; M.A. Andersen Amoco Production Co. Search for other works by this author on: This Site Google Scholar D.C. Thomas; D.C. Thomas Amoco Production Co. Search for other works by this author on: This Site Google Scholar D.C. Teeters D.C. Teeters U. of Tulsa Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Enhanced Oil Recovery Symposium, Tulsa, Oklahoma, April 1988. Paper Number: SPE-17368-MS https://doi.org/10.2118/17368-MS Published: April 16 1988 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Andersen, M.A., Thomas, D.C., and D.C. Teeters. "A New Formation Wettability Test: The Dynamic Wilhelmy Plate Wettability Technique." Paper presented at the SPE Enhanced Oil Recovery Symposium, Tulsa, Oklahoma, April 1988. doi: https://doi.org/10.2118/17368-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Improved Oil Recovery Conference Search Advanced Search AbstractThis paper describes a technique for inferring formation wettability from measurement on crude oil/brine pairs. This dynamic Wilhelmy plate technique yields a quantitative measure of wettability in a form which is directly comparable to other forces in the reservoir. Exposure to air affects the measured wettability of crude oil, and a device is described for avoiding contamination.IntroductionFormation wetting preference affects the success of most conventional and enhanced recovery methods. Waterflood performance depends on the amount of imbibition which can be expected of a reservoir and oil recovery from EOR Methods is affected by the formation wettability. Matching and predicting performance successfully depends on the ability to determine the degree of wetting preference of the formation. The relative permeability, capillary pressure, electrical response, and occasionally the rock mechanical response all depend on the position of the fluids in the pores. These details have been covered in a series of exhaustive review papers by Anderson.Every technique for estimating formation wettability has drawbacks. The easy tests are qualitative and the quantitative tests are expensive and time-consuming. The dynamic Wilhelmy plate technique described here provides an inexpensive and easy-to-understand quantitative wettability test. The result of the test is a physically meaningful value which can be directly compared to other forces in the reservoir.Wetting character is divided into three regimes usually based on advancing contact angle: water-wetting for angles less than 75 oil-wetting for angles greater than 105, and intermediate-wetting for contact angles between 75 and 105. Because the dynamic Wilhelmy wettability test determines both advancing and receding contact angles, it distinguishes another characteristic wetting in crude oil/brine systems, termed "hybrid" wetting, in which the water-advancing contact angle is greater than 90 and the water-receding contact angle is less than 90. In a hybrid system, whichever liquid is in contact with the surface tends to remain in contact with the surface until it is displaced because of other overriding forces. In this paper, systems with both advancing and receding adhesion tensions greater than zero are termed water-wetting; both adhesion tensions less than zero are termed oil-wetting; and those for which the adhesion tensions switch sign as described above are termed hybrid-wetting.This paper discusses the use of the dynamic Wilhelmy plate technique for evaluation of the wettability of several crude oil/brine systems. A method for performing the tests in the absence of air is described.Discussion of the MethodWilhelmy described the basic technique for measuring surface and interfacial tensions (IFT) in 1863. It has been used by surface chemists for many years, primarily to study vapor/liquid/solid interfaces. A computer-controlled device has been developed for studying both vapor/liquid/solid and liquid/liquid/solid interfaces. A thin plate is suspended from a computer-monitored microbalance over a vessel containing oil and brine. A computer-controlled stepper motor moves the vessel upward causing the plate to pass through the air/oil interface and the oil/brine interface. Multiple wetting cycles can be performed under computer control without disturbing the system.P. 529^ Keywords: anderson, reservoir, upstream oil & gas, enhanced recovery, adhesion tension, waterflooding, brine, crude oil, interface, oil brine interface Subjects: Improved and Enhanced Recovery, Waterflooding This content is only available via PDF. 1988. Society of Petroleum Engineers You can access this article if you purchase or spend a download.