scription:TITLE: Water based drilling fluid additive and a preparation method thereof
FIELD OF THE INVENTION
The present invention relates to the field of nanoscience technology in oil and gas industry. More particularly, the present invention relates to an additive based on agro-based cellulose and nanoparticles for water based drilling fluids.
BACKGROUND OF THE INVENTION
Developments of new oilfields are identified in complex environment, such as, high pressure and high tempefature (HPHT) reservoir conditions or in deeper offshore, which attract challengés while designing drilling fluid (also referred as drilling 'mud') jobs. Various kinds of drilling fluids, such as water-based drilling mud (WBM), oil-based drilling mud (OBM) and their derivatives are being used along with suitable polyrifer and clay additives. The system provides wellbore stability, low torque and drag, éxéellent fluid loss control and filter cake quality, appropriate
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rheological properties for cleaning the hole, and temperature stability. The disadvantages are high cost, environmental limitations, disposal problems, health and safety issues, and detrimental effect on drilling and completion pay zone. The selection of a water based mud (WBM) over oil based mud (OBM) appears to be the trend being foliowed due to environmental concerns in-spite of their drawbacks. Nanofluids show potential use in applications related to upstream oil and gas industry to improve the performance of several processes such as exploration, drilling and completion, production and enhanced oil recovery operations. Recent studies have addressed the use of nanoparticles to solve drilling related issues which includes pipe sticking, lost circulation, torque and drag.. The cellulose (lignocellulose materials) occurrence is found in woods and common source, such as leaves, aquatic agro-waste plant, and other plant substances. These cellulose that

comprises of lignin, hemi cellulose, and a considerably tracé quantity of lignin other elements such as iron, potassium, phosphorus etc.
One of the prior art US20020147113A1, discloses a method and composition of improved additives for use in control of lost circulation, fluid loss and/or seepage loss of drilling fluid during drilling operations. In particular, the additive is formed such that the additive is incorporated into the drilling fluid with much greater speed than powdered or ground additives of similar components. The dense additive can be created by grinding of the lost circulation and seepage control material to produce a small partiele size and applying pressure to the lost circulation and seepage control material such that it densifies and is forced through apertures for creation of a pelletized dense additive, whereas the pelletized dense additive is made from cattle feed cake from various materials such as cotton seed, wherein the organic material is selected from the group substantially consisting of ground wood, pine bark, fruit pomace, vegetable pomace, yellow pine, pine bark, com cobs, peanut hulls, pecan pits, almond shell, corn cob outers, bees wings, cotton burrs, kenaf, silage, oat hulls, rice hulls, seed shells, sunflower, flax, linseed, cocoa bean, feathers, peat mossjute, flax^ mohair, wool, sugarcane, bagasse, sawdust, bamboo, cork, popcorn, tapioca, grain sorghum, soluble gums and combinations thereof.
Another prior art US20110312857A1, discloses an invention relates to the drilling, drillsin and-completion. fluids and-related drilling fluids for an oil and gas field applications. The fluid contains nanoparticles for in use of hydrocarbon drilling and recovery process such as drilling, drill in, completion and the like. The nanoparticles include single walled carbon nanotube, multï walled carbon nanotube, and combinations thereof.
Yet another prior art US20150210912A1, discloses an invention details about the multifunctional mud additive that is capable for stable, long lasting and homogenous water based drilling fluids containing nanoparticles, micro particles and combination thereof.

Yet another prior art US20160168449A1, discloses an invention details about the fracturing fluid system for increasing hydrocarbon production in subterranean reservoir formation. The fluid fracturing consists of base fluid and fluid composition which includes a base polymer an acrylamide polymer. The nano cross linker includes nanomaterial and a cross linker. The nanomaterial includes group consistihg of silica, cellulose, carbon base materials and combinations thereof.
Another prior art US20160251561A1, discloses an details about the preparation of super paramagnetic lipophilic nanofluids as well as drilling fluid additives based on aforementioned nanofluid which improves the properties of walls or mud filter cakes.
There is a need for a design and a development of nanofluids based on agro-based cellulose and nanoparticles for water based drilling fluids, which can overcome the challenges in drilling problems including formation damage, pipe sticking, circulation loss, poor hole cleaning and fluid losses encountered in deviated wells under- high pressure' and high temperature (HPHT) conditions in oil and gas industry, to improve their functional properties including thermal stability, rheological and filtration properties thereof.
OBJECT OF THE INVENTION
Accordingly, the primary object of the present invention is to provide a novel drilling fluid by addition of agriculture waste cellulose with nanoparticles as nanofluids.
1. The primary object of the present invention is to provide an additive for water based drilling fluid, which is eco-friendly in nature and having corrosion resistance.
2. It is another object of the present invention to provide potential solutions for

the development of improved water-based drilling mud (WBM).
3. It is another object of the present invention to improve the stability of nanofluids with metal oxide nanoparticles.
4. It is even another object of the present invention to improve electrical and thermal properties of water based drilling mud agricultural waste cellulose and nanofluid.
5. It is yet another object of the present invention to improve rheological properties of water based drilling mud agricultural waste cellulose and nanofluid.
6. It is another object of the present invention to improve filter cake thickness of water based drilling mudagricultural waste cellulose and nanofluid.
7-. It is even another- object of the present invention to provide cellulose based nanofluid as an additive which is efficiënt to control rheology and filtration properties.
SUMMARY OF THE INVENTION
It will be undèrstood that this disclosure is not limited to the particular systems, and methodologies described, as there can be multiple possible embodiments of the present disclosure which are not expressly illustrated in the present disclosure. It is also to be undèrstood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present disclosure.
According to the basic aspect of the present invention, there is provided a water-based drilling fluid additive, the additive comprising of a base fluid selected from the

group consisting of water which is initially purifïed by means of deionization and filtration techniquej polyethyleneglygol, propylene and even crude oil, a nanoparticle selected from the group consisiting of silica oxide, ZnO, CuO, Tio2, MgO, SWCNT, MWCNT, CNT which are added with said base fluid to form nanofluid. The prepared nanofluid which is then mixed with various kinds of agro based cellulose along with the dispersing agent in the form of colloidal dispersion. The dispersing agent is provided as cetyl tetra ammonium bromide (CTAB), sodium lauryl sulphonate (SLS), sodium dodecyl sulphate (SDS), SDBS, TMAH.
According to another aspect of the present invention, there is provided a method of preparing additive for water-based drilling fluids, comprising the steps of: extracting cellulose from agro based wastes. The agro based wastes are treated with the 10% alkali solution on a stirrer which is kept for two hours and allowing it to settle down for twenty four hours and repeatedly treating with hot water, after twenty four hours, to thereby achieving separation of cellulose* A thermal hot air oven in which cellulose separated from agro based waste is kept for 48 hours is provided. A powdered form of cellulose after 48 hours is obtained, which is then crushed with Hamilton bleacher. A nanoparticle selected from the group consisiting of ZnO, CuO, Tio2, MgO, SWCNT, MWCNT, CNT is added with base fluid which is selected from the group consisting of water, polyethyleneglygol, propylene and even crude oil to form nanofluid. An additive is prepared by mixing of nanofluid with various kinds of agro based cellulose along with the dispersing agent in colloidal dispersion form. The nanofluids for functional properties of water based mud at high pressure and high temperature (HPHT) can be prepared which can overcome the challenges encountered in deviated wells under HPHT conditions. The effect of novel additives is analyzed on the rheology of the drilling fluid and filtration of the drilling fluid.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The above set forth and other features of-the invention are made more apparent in the ensuring detailed description of the invention, when read in conjunction with the accompanying drawings, wherein:
Fig. 1 illustrates the flow diagram of the preparation method of water based drilling fluid additive, according to the present invention.
Fig. 2A, illustrates the schematic representation showing the analysis of the characterization of powdered form cellulose extracted from cotton seed by using XRD analysis, according to the present invention.
Fig. 2B, illustrates the schematic representation showing the analysis of characteri zation of powdered form cellulose extracted from ground nut husk by using XRD analysis, according to the present invention.
Fig. 3A, illustrates the schematic representation- showing the analysis of the characterization of cellulose extracted from.cotton seed by using FTIR analysis, according to the present invention.
Fig. 3B, illustrates the schematic representation showing the analysis of the characterization of cellulose extracted from ground nut husk by using FTIR analysis, according to the present invention.
Fig. 4A-4D, illustrate the SEM images showing the analysis of the stability of formulated nanofluids at various concentrations, according to the present invention.
Fig. 5A-5D, illustrate the schematic representation of the DLS images showing the analysis of characterization of dispersion of nanoparticles in the nanofluids, according to the present invention.

DETA1LED DESCRIPTION OF INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS
The preferred embodiment of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilied in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessary obscure the present invention in detail.
With reference to the figure 1, the invention is illustrated as applied to, the flow diagram of the preparation method of water based drilling fluid additive, comprising the steps of: extracting cellulose from agro based wastes, treating agro based wastes with the 10% alkali solution on a stirrer which is kept for two hours and allowing it to settle down for twenty four hours and repeatedly treating with hot water, after twenty four hours, to théreby achieving separation of cellulose. A thermal hot air oven in which cellulose separated from agro based waste is kept for 48 hours is provided after which a powdered form of cellulose is obtained, which is then crushed with Hamilton bleacher. A nanoparticle selëcfed from the group consisiting of zinc oxide (ZnO), cupric oxide (CuO), titanium dioxide (Tio2), Magnesium oxide (MgO), single walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT) and CNT is added with base fluid which is selected from the group consisting of water, polyethyleneglygol, propylene and even crude oil to form nanofluid. The additive is prepared by mixing of nanofluid with various kinds of agro based cellulose along with the dispersing agent in colloidal dispersion form.
Preferably, the alkali solution is sodium hydroxide (NaOH) solution. The obtained agro based wastes including cotton seed, rice husk, groundnut husk, rice straw, pista shell, seasame, sugarcane waste, coconut shell are provided.

In one embodiment of the present invention, there is also provided a water based drilling fluid additive comprising of: a base fluid selected from the group consisting of water which is initially purifïed by means of deionization and tiltration technique, polyethyleneglygol, propylene and even crude oil, a nanoparticie selected from the group consisiting of ZnO, CuO, Tio2, MgO, SWCNT, MWCNT and CNT which are added with said base fluid to form nanofluid. The prepared nanofluid which is then mixed with various kinds of agro based cellulose along with the dispersing agent in the form of colloidal dispersion. Moreover, said dispersing agent which is as cetyl tetra ammonium bromide (CTAB), sodium lauryl sulphonate (SLS), sodium dodecyl sulphate (SDS), SDBS, TMAH.
The stable nanofluids are prepared by two step method and it is formulated as shown below.

Further to the above preparation, the nanofluids can be preparedby varying the concentrations by using Surfactant such SDBS, SLS, TMAH, with water as base ■ medium solution along with the combination of agro based cellulose extracted from Rice husk, Sugarcane waste, Starch.
With reference to the Figures 2A and 2B, the invention is illustrated as applied to, the schematic representation showing the analysis of, the characterization of powdered form cellulose extracted from cottön seed by using XRD analysis, and the characteri zation of cellulose extracted from ground nut husk by using XRD analysis respectively, according to the present invention.

When. comparing the X ray diffraction measurement for cotton seed with cellulose obtained for Nurrudin et al. (2011) shows that the peak value obtained for 2 theta (deg) 20 with the corresponding intensity 600 shows that cellulose obtained is closely associated Lignin cellulose of type I-Alpha as shown in the table below.
When comparing the X ray diffraction measurement for Ground nut husk with cellulose obtained for Nurrudin et al. (2011) shows that the peak value obtained for 2 theta (deg) 30 with the corresponding intensity 163 shows that cellulose obtained is closely associated Lignin cellulose of type I-Alpha.
With reference to the Figures 3A and 3B, the invention is illustrated as applied to, the schematic representation showing the analysis of, the characterization of cellulose extracted from cotton seed by using FTIR analysis, and the characterization of cellulose extracted from ground nut husk by using FTIR analysis, according to the present invention. The results obtained through the FTIR analysis for the cotton seed

with cellulose structure reveals that it has poly saccharide (- OH and - COOH) group present. The peak obtained at range from 3000 to 4000 cm'1 shows that there is OH present, hence it is observed that it belongs to I alpha cellulose. Similarly, the results obtained through the FTIR analysis for the ground nut husk powder with cellulose structure reveals that it has poly saccharide (- OH and - COOH) group present. The peak obtained at range from 3000 to 4000 cm-1 shows that there is OH and also carboxyl group present, hence it is observed that it belongs to I alpha cellulose.
With reference to the Figures 4A-4D, the invention is illustrated as applied to, the schematic representation of the SEM images showing the analysis of the stability of formulated nanofluids at various concentrations. The nanofluid is formulated and then subjected to stable studies by using scanning electron microscopic (SEM) analysis. The SEM results show that the ZnO nanoparticles interact with water-soluble polymers, resulting in loosely-packed and randomly-distributed spherical-shaped particles in the polymer solution. Figure 4A and 4B show results for 0.3wt% of ZnO and CuO nanofluids prepared with 0.5wt% of SDS polymer in water. Figure 4c shows results for 0.3wt% of ZnO nanofluids prepared with CTAB. The polymer solution forms a mesh-like structure into which the spherical-shaped nanoparticles get embedded. The increased concentration of nanoparticles has shown to form agglomerations, which are an indication of lower stability. This nanofluid exhibits reduced agglomeration due to the interaction of polymer chains surrounding the ZnO particles. The size of the ZnO nanoparticles increases with concentration. ZnO also tends to reduce the size by interacting with SDS to form a polymer (packing effect).
With reference to the Figures 5A-5D, the invention is illustrated as applied to, the schematic representation of the DLS images showing the analysis of the characterization of dispersion of nanoparticles in the nanofluids. The nanofluid is formulated and then subjected to study of stability by using dynamic light scattering (DLS) studies. DLS measurements are carried out to characterize the dispersion of nanoparticles in the Nanofluid.
It is observed that from the figure 5A, CuO (0.1%) in CTAB (0.5%), the partiele ranges from 15 nm to 30nm on the first day and then it slightly varies from 20 nm to

35 nm on the third day, like wise ZnO (0.1%) is compared on the same results show from the figure 5B the partiele varies from 10 nm to the 20 nm and on the third day it slightly moves to 23 nm.
It is emphasized that the Abstract of the Disclosure is provided to allow a reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein," respectively. Moreover, the terms "first,""second," "third," and so forth, are used merely as labels, and are not intended to impose numerical requirements on their objects.
Without further description, it is believed that one of ordinary skill in the art can, using the preceding descrip'tión and the illustrative examples, make and utilize the present invention and practice the claimed methods. It should be understood that the foregoing discussion and examples merely present a detailed description of certain preferred embodiments. It will be apparent to those of ordinary skill in the art that various modifications and equivalents can be made without departing from the spirit and scope of the invention.

5. Claims: I Claim:
1. A water-based drilling fluid additive, the additive comprising:
a base fluid selected from the group consisting of water, polyethyleneglygol, propylene and even crude oil;
a nanoparticle selected from the group consisiting of ZnO, CuO, Tio2, MgO, SWCNT, MWCNT, CNT which are added with said base fluid to form nanofluid;
wherein, said prepared nanofluid which is then mixed with various kinds of agro based cellulose along with the dispersing agent in the form of colloidal dispersion.
2. The water-based drilling fluid additive as claimed in claim 1, comprising said dispersing agent which is selected'from the group consisting of cetyl tetra ammonium bromide (CTAB), sodium lauryl sulphonate (SLS), sodium dodecyl sulphate (SDS), SDBS, TMAH.
3. The water-based drilling fluid additive as claimed in claim 1, comprising said base fluid including water which is initially purifïed by means of deionization and fïltration technique.
4. A method of preparing additive for water-based drilling fluids, comprising the steps of:
extracting cellulose from agro based wastes;
treating agro based wastes with about 10% alkali solution on a stirrer which is kept for two hours and allowing it to settle down for twenty four hours and repeatedly treating with hot- water, after twenty four hours, to thereby achieving separation of cellulose;
providing a thermal hot air oven in which cellulose separated from agro based waste is kept for 48 hours;

obtaining, a powdered form of cellulose after 48 hours, which is then crushed with Hamilton bleacher;
adding a nanoparticle selected from the group consisiting of ZnO, CuO, Tio2, MgO, SWCNT, MWCNT, CNT with base fluid which is selected from the group consisting of water, polyethyleneglygol, propylene and even crude oil to form nanofluid;
preparing an additive by mixing of nanofluid with various kinds of agro based cellulose along with the dispersing agent in colloidal dispersion form.
5. The method of preparing additive for water-based drilling fluids, comprising wherein said alkali solution is sodium hydroxide (NaOH) solution.
6. The method of preparing additive for water-based drilling fluids, wherein said obtaining agro based wastes selected from the group consisting of atleast one of cotton seed, rice husk, groundnut husk, rice straw, pista shell, seasame, sugarcane waste, coconut shell.