La presente invention concerne des procedes se rapportant generalement a la preparation et l'introduction d'un melange de fluides dans un volume confine, et plus specifiquement dans un volume annulaire situe entre deux colonnes de tubage orientees de facon concentrique a l'interieur d'un puits produisant un fluide d'hydrocarbure. Les melanges de fluides de l'invention se pretent particulierement bien a la gestion de la pression dans des volumes localises. Les melanges de fluides comprennent au moins un monomere polymerisable et au moins un inhibiteur. Les traitements et procedes de l'invention permettent de conserver, de transporter et/ou d'injecter le melange de fluides dans des volumes localises, par exemple dans un volume localise defini par des colonnes de tubage de puits concentriques.

Proposal Described are proof-of-concept developments to form a seal for mitigating sustained casing pressure caused by annular pressure buildup. Annular pressure can result from numerous sources, including tubing leaks, loss of isolation potential within the cement column because of poor mud displacement, free water-induced channels, stress fractures, and failure of the cement to cover all potential sources of annular pressure. In most cases, annular pressure is not observed at the wellhead until the well is placed on production, making it difficult to identify, access, or remediate the pressure source. A new and novel approach to remediation has been tested in which a low-melt-point alloy metal is dropped down the backside of the casing where annular pressure has been observed. The metal is allowed to accumulate at the top of cement or other physical barrier, melted with an induction-heating tool, and allowed to cool and solidify. This process forms an annular seal to stop fluid communication between the formation and wellhead. This method was demonstrated within a full-scale, simulated well section. An electromagnetic induction tool provided sufficient localized heating to completely melt solder-type alloy metal placed between concentric casings. Subsequent pressure-testing verified that a complete melt, sufficient to provide an effective seal against fluid pressure, was achieved in both water- and synthetic-based drilling fluids. Shear-bond test results of various alloys were equal or superior to cement, and the solid-liquid phase transitions (set points) occurred at precise temperature levels. All metals tested contained bismuth because of its unique characteristic of expanding upon solidification to provide enhanced pressure-containment performance. Full-scale testing was conducted using 17-ft long concentric annular models constructed of 8-in. and 5-in. diameter steel pipes. Subsequent field-testing is currently being planned.

Abstract Annular gas pressure, also known as sustained casing pressure (SCP), is a common problem and potential threat to the safety of personnel and equipment, as well as to the environment. Improved means of primary cementation and life-of-the-well simulations show promise for preventing future annular gas-flow problems. However, there has been little success in eliminating SCP, once developed, without jeopardizing the economic life of a well. Possible solutions to SCP in the form of remediation include bullheading cement, injection of zinc bromide brines into the well's annulus, or use of expensive resins to seal the annulus. A proposed solution that can compensate for the drawbacks of the above options and has shown promise on small-scale physical models is palletized alloy-metal. This solution involves placing palletized alloy-metal into the well's annulus, heating the alloy-metal above its melting point, and then allowing the alloy-metal to cool. These steps form a continuous alloy-metal plug in the well's annulus. Data and conclusions documented in this paper are from full-scale pipe-in-pipe and pipe-in-sandstone geometry models having the following scope: Geometry of 5 ½ × 8 ½-in. pipe-in-sandstone and 10 ¾ × 13 ⅜-in. pipe-in-pipe configurations Model length limited to 15 ft and deviated at 30° from vertical Alloy-metal pellets placed and activated with water-based drilling fluid present in annuli Temperature limited to 200°F Results are also documented by dissecting the models and photographing the exposed cross-sections. Information gathered in this testing will help with the field introduction of this technology.

The extraction of slate for use as a construction material generates large quantities of waste (between 75% and 90% in weight), which are dumped on landfill sites, with the ensuing technical, economic, environmental, and social problems. One possible way of reusing this raw waste is through its thermal activation to produce a new cementitious material for the manufacture of eco-efficient cements.An assessment is presented in this study of the chemical, mineralogical and pozzolanic properties of ash waste, activated at 1000 °C over 2 h, as well as a study of the main technical properties of blended cements prepared with 10% and 20% slate ash. The results show the high pozzolanic activity of the slate ash, principally over the seven first days, forming CSH gels as a principal hydrated phase of the pozzolanic reaction, followed by randomly interstratified chlorite/smectite phases and monosulfoaluminate [C3A·SO4Ca·12H2O]. These blended cements prepared with 10% and 20% activated slate waste comply with both the physical and the mechanical requirements of current European standards.