One of the dynamically developing applications of boron compounds produced by Eti Maden is the oil and gas industry. Boron compounds are used in a number of reagents, in particular, in the composition of borate crosslinkers for hydraulic fracturing (or fracking), in the composition of drilling muds, etc.
Hydraulic fracturing is one of the methods to intensify the operation of oil and gas wells and to increase injection capacity of injection wells. The method is to create a highly conductive cracks in the target formation ın order to provide the inflow of produced fluid (gas, water, condensate, oil, or a mixture of them) to the bottom of the well.
After hydraulic fracturing, the well rate, as a rule, increases by 5-10 times. The method allows to “revitalize” idle wells, where the extraction of oil or gas by traditional methods is no longer possible or unprofitable. In addition, at present time, the method is used to develop new oil reservoirs, the extraction of oil from which by traditional methods is unprofitable due to the low production rates. It is also used to extract shale gas and compacted sandstone gas.
The essence of the method is as follows: fracturing fluid is pumped into the well at pressure and flow rate high enough to split the rock and create cracks with specified size in it. Sand or ceramic material (proppant) are added to the working fluid to keep the crack open once pumping stops and pressure decline.
When conducting hydraulic fracturing, in most cases, an aqueous solution of high molecular weight polymers, such as guar gum and its derivatives, are used as a working fluid. Special reagents, so-called crosslinkers, are used in order to give working fluid the necessary technological properties and in particular the viscosity, which is necessary to create the required cracks and keeping the proppant inside of the crack. Since the mid-90s of the last century, compositions based on boron compounds have been mainly used as crosslinkers. The crosslinking effect of the working fluid is provided by the introduction of boron oxide B2O3. Increasing the viscosity of the working fluid using a borate crosslinker is more cost effective than increasing the viscosity due to increasing the amount of guar gum.
Currently, the main boron compounds produced by the company Eti Maden for the production of crosslinkers are:
Recently, due to increasing requirements for the quality characteristics of the crosslinkers and the creation of new brands of crosslinkers for a particular type of wells, manufacturers of crosslinkers show great interest in the following compounds:
The most preferred component of the borate crosslinker, which is used in guar gum based fluids, is ulexite due to its delayed solubility in this fluid. Etiproducts Ltd. proposes ulexite with extremely small particle size of 45 microns, which reduces risk of mixer filter element clogging.
In the process of drilling an oil or gas well, a special drilling mud is used. Its usage makes it possible to carry out drill cuttings from the bottom of the well, keep the drill bit cool, clean and lubricate it during drilling, increase the resistance of pipes and equipment to corrosion, prevent screes and collapses, form a filtration bed in the rock, maintain pressure that prevents penetration of formation fluid into the wellbore, etc.
Modern drilling muds can have different compositions, viscosity, weight and other characteristics. Their preparation is carried out taking into account the characteristics of the raw material, selected technologies, conditions of use, etc. This is a complex multicomponent disperse system of emulsion, aeration and suspension type liquids. Various reagents are used to control the properties of drilling fluids. For example, a clay swelling inhibitor.
Boron-containing products are contained in clay swelling inhibitors, such as borosilicate inhibitors. This reagent is used to reduce the rate of clay hydration, showing inhibitory ability. It reduces the viscosity of dispersed systems of drilling muds, which contain suspended particles of clay; it stabilizes the filtration and rheological properties of dispersed systems of drilling muds; it stabilizes unstable clay deposits. It is effective in water based drilling muds.
The advantages of this reagent include the fact that it mixes easily with drilling mud and does not require special equipment for dispersing the reagent in the system.
Etiproducts Ltd. suggests using boric acid (H3BO3) in clay swelling inhibitors.