New Cementing Technology Cures 40-Year-Old Squeeze Problems

Abstract

Abstract Remedial cementing using recently developed engineered micro-cement slurries allows small channels to be efficiently filled with cementitious materials, developing a permanent, high quality seal with high compressive strength and low permeability. Deeper penetration is achieved over conventional micro-cement slurries by improving axial fluid loss control through particle size distribution adjustments, and not from using small particles alone. This new technology has been extremely effective in remedial cement squeeze treatments, where synthetic and conventional cement systems have failed over the past 40 years. The packing volume concept separates engineered slurries from conventional slurries. Engineered micro-cement slurries incorporate a particle size distribution that allows deeper penetration without bridging, premature viscosification or dehydration. The slurry has extremely low fluid loss, low plastic viscosity, lower yield points and better slurry stability with respect to free water and sedimentation. This slurry has superior injectivity over previous oil field cements, however, placement procedures do not follow conventional cement squeezing wisdom. When this material is placed into the channel, crack or perforation, the typical increase in pressure response that is seen during conventional squeeze treatments may not be observed. This technology has been proven to be successful in more than forty wells to-date. In the New Hope field of East Texas, and in particular the Bacon and Hill Sand formations, up to nine squeeze attempts were performed on individual wells, without establishing a permanent hydraulic seal using various conventional cement systems and techniques. Conversely, in the same field, seven barrels of the engineered micro-cement slurry were placed on the first attempt, achieving the isolation required for re-completion. The application of this technology has also experienced good success in the Canadian shallow gas, and heavy oil markets. The shallow gas fields are located in Southeastern Alberta, near Medicine Hat, and the heavy oil fields are located in Northeastern Alberta in the Wainwright area.