Planning for Better Formation Consolidations Using Fluid Displacement Studies
Authors: Stein N. , Watts J.W. 
Published: December 2007

This paper was prepared for the 48th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Las Vegas, Nev., Sept. 30-Oct. 3, 1973. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgement of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

One means of controlling sand production from weak sand intervals is to treat the formation with chemicals that will add cementitious materials between sand grains. This paper deals with possible treatment failures that can result from poor displacement patterns of the chemicals injected into a formation. Successive injection of a series of flushes are normally required to consolidate a formation. Mathematical model studies were made of fluid fronts, considering such variables as (1) flush volumes to blend fronts, (2) viscosity of the flush fluids and (3) different perforation lengths. Results of the studies should perforation lengths. Results of the studies should be particularly useful in successful consolidation of longer perforated intervals. For instance, results showed that failure to treat successfully a long uniform formation interval with one type of consolidation technique could be caused by excessive flushing of the plastic solution injected into the sand; this flushing occurs adjacent to the wellbore near the top and bottom of the perforated interval. A method is given for estimating the volume of fluid flushing these critical zones. Such data can be used to design realistic laboratory experiments to evaluate how effective a consolidation technique will be for a particular well treatment.

Introduction

One means of controlling sand production from weak sands is to treat the formation with certain chemicals that cement formation particles together. Since a series of successive particles together. Since a series of successive fluid injections are normally used in such commercially available treatments, there is the possibility that a consolidation treatment can possibility that a consolidation treatment can fail if poor displacement by the sequential injections takes place, even though all other precautions to obtain a successful treatment precautions to obtain a successful treatment are taken. This paper presents a mathematical model that can be used to show the movement of successively injected fluids in the sand around the wellbore. The results of well model studies can be used to increase the success ratio of successful consolidations of formation sands, especially in wells having long perforated intervals.

An example of how the results of displacement studies can be utilized is also included in this paper. The variables considered in this example paper. The variables considered in this example include (1) volumes required for adequate displacement, (2) viscosity of the first injected fluid and (3) different perforation lengths. Hopefully, this paper will encourage the use of laboratory tests based on model studies to deal satisfactorily with one part of the many requirements for successful sand consolidation. The percentage of successful sand-control treatments should increase if such an approach is followed.