Well completion fluids are solid-free liquid that are used for completion of oil wells. It is intended to minimize formation damage and control formation pressure. Completion fluids improve the productivity of the well by preventing damage to the producing zone and facilitating repair, clean out, and completion of the well during the completion phase. They are low-solid mud or salt solution (brines i.e. the mixture of water with chlorides, bromides and formats (salt of formic acid)) that is used for well testing and also upon a well’s completion. The fluid is placed in the well which helps in the final operations prior to initiation of the production such as downhole valves and setting screens production.
Completion fluids have a high pH content and ionic composition and should be chemically compatible with the reservoir formation and fluids. It is typically filtered to a high degree to avoid introducing solids to the near-wellbore area. Completion fluids are typically brine, but in theory, they could be any fluid of proper density and flow characteristics. Due to solid content, pH value, and ionic composition, it is seldom that regular drilling fluid is suitable for the completion process
During the process, workover fluids are used during remedial work in the well e.g. removing tubing, replacing a pump, logging, reperforating, and cleaning out sand or other deposits.
Both workover and completion fluids are used during the part to control the well pressure in order to stop the well from blowing out while it is being completed or worked over, or to prevent the collapse from overpressure
It is to be noted that specially formulated fluids are used while completion and workover operations to minimize the damage in the formation. Formation damage from solids and filtrate invasion can be minimized by treating the well in a near-balanced condition, i.e., when the wellbore pressure is close to the formation pressure.
In high-pressure wells, it is often necessary to treat the well under over-balanced or under-balanced conditions. If over-balanced, the treating fluids are designed to temporarily seal the perforations to prevent the entry of fluids and solids into the formation. If under-balanced, the treating fluids are designed to prevent the entry of solids from the formation into the wellbore.
Once the completion is incased, the final stage is to make a connection between wellbore and the formation which is done by running perforation guns to blast holes.
fyndsupplier is customized with an outside-in approach with e-procurement service, i.e. we are guided by the belief of customer value creation. We effectively communicate with customers and suppliers across the globe varying all time zones
Sometimes when the well is completed, further stimulation is done to achieve the planned productivity. The stimulation techniques can be:The stimulation techniques can be:
1. Acidizing for cleaning up the formation thus improving the flow of reservoir fluids.
2.Fracturing by creating and extending fractures from the perforation tunnels by increasing the surface area for formation fluids in order to flow into the well.
3.Acidizing and fracturing by using explosives and injections to increase acid-rock contact.
4. Nitrogen circulation by using coiled tubes to pump nitrogen at high pressure into the bottom of the borehole in order to circulate the brine particularly in gas fields
Water Injection Chemicals
To maintain the pressure in the reservoir after primary recovery, water is injected to continue the production; it is commonly known as secondary recovery.
In fact, almost all the produced water is re-injected back into the reservoir but most of the time it is also not sufficient. Therefore, nearby available water resources from the river, bore well or sea becomes handy by using lift pumps
Water increases the recovery factor and maintains the production rate of a reservoir for a longer period. While utilizing the water from the resources the problems like oxygen corrosion, presence of SRBs, dissolved solids, organic matter, and scale forming minerals are common and that is where water injection chemicals from oilfieldin are going to be in use.
Oxygen flourishes the living organism in the reservoir, debris may clog the well, organic matter can multiply themselves and chemicals may induce scaling.
Filtration is used to clean the water and remove impurities like sediments, algae and sand, typical filtration is up to 2 micrometers but this can also depend on reservoir requirements. Pump strainers are also used to stop small size material entrances
The effect of steam and water injection is to increase the thermal mass by dilution and thereby reduce peak temperatures in the flame zone. Water or steam injection is a technology that has been demonstrated to effectively suppress NOx emissions from gas turbines. With water injection, there is an additional benefit of absorbing the latent heat of vaporization from the flame zone. Depending on the initial NOx levels, such rates of injection may reduce NOx by 60% or higher. Water or steam injection is usually accompanied by an efficiency penalty (typically 2–3%) but an increase in power output (typically 5–6%).
Some of the examples of chemicals that can build up reservoir pressure to a depleted reservoir are:
.Silicon and glycol base antifoams to treat oil and water phases. Foaming reduces efficiency and can easily hinder the whole production.
.Polymers and iron compounds as coagulants, flocculants and water clarifiers to treat water inlet from sea, borewell or river water resources.
.Bisulphate base chemicals to reduce oxygen content in injected water to reduce the corrosion. Free oxygen shall be removed as much as possible. Minimum oxygen content allowed for injection to reservoir is 10 ppb.
.Cyclic amine base and glycol base to treat liquid as well as gaseous fluids.
.Biocides or surfactants to control kill bacteria
..Polymers, ter-polymers, tetra-polymers to treat variety of oilfield water.
.Imidazoline base mixture of amine surfactants as corrosion inhibitors
.Nano filters to separate sulfate ions that enable installing sulfate reduction molecules on the floating storage units. These can help in reducing sulfate concentration up to 50 ppw.
Some of these chemicals act to reduce the viscosity of the oil or to increase the viscosity of the water while others act as to improve the relative permeability to water which often results in stripping more oil off of such surfaces helping the process easier.
MUD CHEMICALS
Drilling muds or drilling fluids are a thick, viscous fluid mixture that is used in drilling operations to carry rock cuttings to the surface, and also lubricate as well as cool the drill bit.
Mud Chemicals are water/oil-or-synthetic based mud used in the water well drilling operation.
The main functions of drilling fluids include
Drilling muds are divided into
Water-based drilling muds
Freshwater, seawater, naturally occurring brines or prepared brines
Usually done at conventional vertical wells at medium depths.
Oil-based drilling muds
Direct products of petroleum refining i.e mineral oil or diesel oil.
Better for greater depths or directional/horizontal drilling.
Requires greater stress on the drilling equipment.
Synthetic based drilling muds
Highly refined fluid compound
They provide primary well control of sub-surface pressures by a combination of density and any additional pressure acting on the fluid column (both annular and surface imposed).
Some Mud Chemicals are Barites, Calcium Carbonate, Calcium Chloride, Drilling Detergent, Glutaraldehyde, Amine based oxides, EP Lubricants, H2S Scavenger, Oxalic Acid, Soda Ash, Bentonite, Gaur Gum etc.
E.g. Baritie(Barium Sulfate) to increase the weight of column to stabilize the borehole, d OR Bentonite(to give enough viscosity to carry out cutting chips to the surface.
Many types of drilling fluids are used on a day-to-day basis. Along with their formations, these are used along with appropriate polymer and clay additives for drilling various oil and gas formations.
A mud engineer is an individual who is charged to maintain the drilling fluid or completion fluid system on an oil/gas drilling rig.
Drilling muds are classified on the basis of the fluid phase, alkalinity, dispersion and the type of chemicals used.
Some wells require different types that are to be used at different parts in the hole, or for some types require a combination with others.
The various types of fluidare:
• Air: Compressed air is pumped either down the bore hole's annular space or down the drill string itself.
• Air/water: same as above, with water added to increase the viscosity
• Air/polymer: A specially formulated polymer, is added to the water and air mixture to create specific conditions.
• Water: In offshore drilling, seawater is typically used while drilling the top section of the hole.
• Water-based mud (WBM): Most basic water-based mud systems begin with water, then clays and other chemicals are incorporated into the water to create a homogeneous blend. The most common of these is bentonite, frequently referred to in the oilfield as "gel."
• Oil-based mud (OBM): Oil-based mud is mud where the base fluid is a petroleum product such as diesel fuel. Oil-based muds are used for many reasons, including increased lubricity, enhanced shale inhibition, and greater cleaning abilities with less viscosity. Oil-based muds also withstand greater heat without breaking down.
• synthetic-based fluid (SBM) (Otherwise known as Low Toxicity Oil Based Mud or LTOBM): synthetic-based fluid is mud in which the base fluid is a synthetic oil. This is most often used on offshore rigs because it has the properties of an oil-based mud, but the toxicity of the fluid fumes are much less than an oil-based fluid.
Cement Additives
Cement is made from calcareous and argillaceous rocks like clay, limestone and shale or any other material that contains a higher percentage of calcium carbonate.
The dry material is grounded in fine powder and mixed with correct proportions and adjusted according to the need. This mix is known as kiln feed which is then heated to a certain temperature that results in a material called clinker
The clinker is cooled and mixed with gypsum (to control the setting and the hardening properties of cement slurry) and other products to form a new product called Portland cement.
Additional chemicals are added to control fluid loss, rheology and slurry density to modify the behaviour of cement that allows cement placement under a wide range of downhole conditions.
Thus, Cement additives are the materials that are added to cement to optimize cement properties along with the cement grinding process.
Cement additives can be classified into different types of product group such as grinding aids, to enhance strength and performance and affecting the production process by improving the quality of cement.
These improvements can enhance cement properties depending on the application of the cement. e.g.
Cement additives are boric acid, hematite, tartaric acid, tannin acid, starch etc. in the form of accelerators, retarders, dispersants, extenders, gels, weighting agents, foamers and fluid loss additives.
1.Accelerators: A chemical additive that is used to speed up the normal rate of reaction between cement and water shortening the thickening time of cement and increasing its early strength.
2.Retarders: A chemical additives to decrease the speed of cement hydration and delay setting which allows sufficient time for slurry placement.
3. Extenders: Water absorbing materials which are used to reduce slurry density and increase the yield of cement slurry. This helps in preventing the breakdown of weak formation and loss of circulation
4.Weighting agents: To restrain high formation pressures, weighting agents are used, weighting agents are inert in the cement slurry
5.Dispersants: Friction reducing additives to improve the flow properties of cement slurry.
6.Fluid loss additives: Also known as permeability plugging additive to reduce the rate at which water from cement is forced into the permeable formation
7.Special agents: Materials like Resin or plastic cement, microfine cement, expanding cement, refractory cement, gypsum cement, cements for carbon dioxide resistance, cement additives for permafrost environments, and sorel cement, and latex cement comes under this category.
There are two kinds of activities that are done in cementing
By adjusting the cement quality to meet the demands set by customers, oilfieldin can contribute to the profitability of cement plants.
In an oil and gas well, the primary function of cement are
1. To provide zonal isolation
2.To support an axial load of the casing string
3.To provide support to the borehole
4. To provide casing support protecting against corrosive fluids.
Production Chemicals
Production chemicals are used to enhance the recovery of hydrocarbons from the production unit to achieve optimum performance and effectiveness.
These include clay stabilizers, scale inhibitors, acid corrosion inhibitors, xylene, toluene, asphaltene inhibitors, biocides, demulsifies, scavengers, surfactants, potassium chloride and others.
E.g. Demulsifier intermediates; Emulsion breaking is a complex situation in aspects of oilfield chemistry. To remove water from crude oil economically, we can use demulsifiers to treat a wide range of emulsions including the places where there is high turbulence, low temperatures, high water content and high solid loadings
The increasing demand for production chemicals in the market is driven by increasing production of crude oil, increasing drilling activities and production from existed or ageing oilfields.
Production chemicals are used in oilfield operations to improve production maintenance and recovery from reserves.
Production chemicals are typically injected into the wellbore, well head and flow lines to treat corrosion, emulsions, scale and H2S content.
A chemical production site consists of a wide range of production and utility plants, and they require regular maintenance to improve their efficiency and reliability.
There are 4Cs of production chemicals when it comes to quality
1.Compatibility: Chemicals should be compatible with each other with effectiveness and the production system equipment such as valve elastomeric seals without degrading them.
2.Consistency: Consistency of the chemicals should remain the same and fluidity over the range of temperatures and pressures in the production system should be stable. Even at conditions like reduced pressure such as vaccum, consistency shall remain the same.
Chemicals are usually formulated in solvents such as toluene, glycol or methanol.
3. Cleanliness: It is essential that the chemicals must be cleaned and filtered properly because even a minute quantity of unnecessary solid can plug off the chemical injection valve or the port.
4. Concentration: Chemicals should be at a fairly low concentration to remain economic and not affect the separation process simultaneously.
Chemical production constitutes significant degrees of freedom for the development of bio-refineries, it is constituted that Total Site Analysis (TSA) should be combined with a synthesis approach to screen and preview options of product portfolios and chemical paths that offer high integration potentials for the overall biorefinery
Oilfieldin is dedicated to providing quality, verified and performance-based chemicals, we ensure that the supply chain is seamless, offering a broad range of production chemicals.