Cesium Formate Brine
Kathy Douds
Cesium Formate fluids are ideal as base fluids in a number of industries. These non- corrosive organic monovalent fluids offer a number of performance benefits over traditional brines.
Higher Density: Cesium formate fluids can reach 2.3 sg (19.2 ppg) at saturation. Cesium formate is 83% w/w soluble in water. Traditional divalent chloride and bromide brines are not as soluble, +/- 50% w/w.
Lower Viscosity: Cesium formate fluids have very low viscosities. They range from 5 cps at ambient temperatures to 1 cps at moderate wellbore temperatures.
Solids Free: Cesium formate fluids are solids free. Weighting agents, like barite, are not needed to reach a desired fluid density.
Environmentally Responsible: Cesium formate fluids have been awarded a grouping of "E" by the U.K. Department of Trade and Industry, the most favorable rating.
Non-Damaging: Cesium formate fluids are monovalent and will not interact with reservoir waters to form precipitates. Traditional divalent brines can cause damage through this mechanism.
Thermally Stable: Cesium formate fluids have been field tested in one of the most severe HPHT environments in the North Sea. Cesium formate fluids have performed without problem in numerous wellbore operations at 405 0F.
Lubricious: Cesium formate fluids exhibit lubricity characteristics that are equal to or exceed that of oil muds. Coiled tubing field trials have proven these characteristics.
Cabot Specialty Fluids (CSF), 25025 I-45 North, Suite 385, The Woodlands, TX 77380. Tel: 281-298-9955; Fax: 281-298-6190.
One type of special brine solution is formate. Formate brines are monovalent and are produced from organic formic acid. Formic acid is reacted with sodium hydroxide, potassium hydroxide, or cesium hydroxide to produce solids free sodium formate, potassium formate, and cesium formate brine. Formate brines are not compatible with halide brines.
Single salt formate fluid blends are brines composed of only one salt. Densities typically range from slightly above the density of water such as 8.4 ppg sodium formate solution to 19.2 lb/gal cesium formate solution.
Used in solution as a solid-free completion fluid, where densities of 8.4 to 11.0 lb/gal are required. When properly formulated sodium formate can possibly reduce formation damage because of swelling and dispersion of reservoir clays.
Potassium formate fluids can reach a density of 13.1 ppg at saturation. Potassium formate brines are very inhibitive in not allowing reservoir shales to hydrate, migrate, and/or swell thus preventing formation damage or hole stability issues when used as a reservoir drilling fluid. In addition saturated potassium formate is very lubricious and provides excellent hydrate inhibition. At higher temperatures, potassium formate can also dissolve barium sulfate.
Multi-salt blends are composed of two or more formate brines. The reason the brines are blended is to achieve the desired density and true crystallization temperature (TCT)/pressurized crystallization temperature (PCT) (TCT/PCT) at the lowest cost. Although not economic, sodium, potassium and cesium formate can be blended together.
Sodium and Potassium Formate brines can be blended in densities from 11.0 lb/gal to 13.1 lb/gal. Blends lower than 11.0 lb/gal are made when lower TCTs are needed and/or additional shale inhibition is required.
Potassium and Cesium Formate brines can be blended in densities from 13.1 lb/gal to 19.2 lb/gal. The fluids are blended to achieve the required density and TCT/PCT. Blending the cesium formate with potassium formate also reduces cost.
SAM provides series of cesium compounds with good quality. With our rich experience and knowledge in the cesium series, you can be confident in making SAM your first choice. We offer high-purity cesium compounds powders according to your requirements.
Cesium formate solutions (such as cesium formate brine) are clear brine of high density and low viscosity, and are useful as drilling, completion, intervention and suspension fluids for oil and gas fields in Wells and reservoirs. Cesium formate is quite useful in HPHT (high pressure and high temperature) drilling locations.
Our Cesium Formate (HCOOCs) Powder is stored in a cool, dry, well-ventilated warehouse and will be kept sealed in a tightly closed container. The storage area shall be equipped with suitable materials to accommodate leaks. It will be carefully handled during storage and transportation to preserve the quality of our product in its original condition. It will be packed in vacuum packing in carton or iron drum.
This document provides information about cesium formate brine, including its uses, benefits, and the company that produces it. Specifically:- Cesium formate brine is a high-density, non-toxic brine used for drilling, completing, and suspending deep gas wells. It can have densities up to 143 pcf. - Using cesium formate brine improves economics by allowing faster drilling and completions while improving well safety. It also maximizes reservoir production and definition. - Cabot Corporation produces cesium formate brine from pollucite ore in Canada. It has been used in over 250 deep gas wells worldwide since 1999.Read less
A few months ago I wrote about a new lithium mine at Thacker Pass which is in northern Nevada near the Oregon border. The geologically important area is called the McDermitt Caldera which is an ancient, collapsed volcano, much like Crater Lake (just not filled with water!). It turns out that some folks took another look at the area and decided it was richer in lithium than they thought. In fact, it might be the largest lithium deposit in the world.
During WWII there was not enough domestic uranium to supply the Manhattan Project. About two-thirds of the stuff came from a mine in the Belgian Congo. Thus there is always a strategic interest in local sources of critical minerals.
Metallic cesium, like the other metals listed above, oxidizes immediately on contact with air. Thus none of these elements are found in nature except in compounds. Our laboratory sodium was stored under oil, for example.
Cesium has a number of radioactive isotopes of which Cs-137 is of interest. It is a by-product of uranium fission and thus present in the biosphere. Besides the bomb tests, nuclear power accidents (like Chernobyl) are the culprit. Cs-137 is used in radiation therapy as well as in a variety of gauges, meters, and measuring devices.
By far the most common use for cesium today is in the oil and gas industry. Cesium formate makes a very dense brine which is used as a drilling lubricant. Interestingly the fluids are mostly recovered and recycled, and cesium formate is particularly desirable because it is non-reactive and of low toxicity.
High-density cesium/potassium (Cs/K) formate fluids were successfully utilized from reservoir drilling to upper completion installation in five productive Martin Linge high-rate gas wells. Four wells were completed with openhole gravel pack (OHGP) and one with standalone sand screens.
Cs/K formate reservoir drilling fluid and screen-running fluid were designed with biopolymeric additives and minimal calcium-carbonate-bridging particles. Clear Cs/K formate brine was chosen as gravel pack carrier fluid. The use of Cs/K formate fluids for all stages of the operation reduced the complexity of transitioning between the operational stages. In addition, the reservoir was only exposed to one filtrate without application of damaging weighting solids.
The drilling fluid contributed to successful MPD and delivered wells with very good hole quality in the reservoir, which consisted of interbedded sandstone, coal stringers, and shale. The shale-stabilizing properties of concentrated formate brine-based fluids provided acceptable conditions for extended openhole time and allowed additional logging runs, including pore pressure measurements, under near-HP/HT conditions, before running the screens. One bottom-up cleanout was conducted before the screen-running fluid was circulated in and the screens installed. The spurt and seepage losses were low throughout the drilling and screen-running phases. No breaker treatment was required in any of the wells. All wells have proved to have good initial productivity and high well productivity index.
This abstract is taken from paper SPE 212487 by S. J. Nilsen, H. U. Obrestad, H. Kaarigstad, N. Mansurova, and T. A. Solvoll, Equinor ASA, and J. Lchen, S. Howard, B. Abrahams, and C. Busengdal, Sinomine Specialty Fluids. The paper has been peer reviewed and is available as Open Access in SPE Journal on OnePetro.
Formate brine systems were developed in the late 1980's and early 1990's by Shell Research KSEPL, The Hague, as high temperature fluids for drilling and completion. Since that time, many additional benefits have been found for the fluids, and by 1994, the fluids were considered ideal as the base for completion and drilling fluids for a variety of demanding environments.
The various formate brines (sodium, potassium, and cesium formate) have been subject to a variety of test regimes by major operating and service companies, as well as environmental testing facilities, and are quite possibly the most tested new drilling fluids today.
Early acceptance of the fluids was hindered by lack of availability and service, though Shell and Statoil both used formate systems successfully. With the emergence of Forbrico as a commercial distributor and service agent for the formates, it is expected that widespread use of these system will soon occur.
The true value of a fluid system can never be fully predicted on the basis of laboratory data alone, no matter how thorough. There is no substitute for field experience, to confirm or deny the predicted performance, and to discover previously unknown qualities, both good and bad. This paper will summarize several uses of the formate fluids in applications and document the first reclamation of a whole formate mud system.