AU2013100002A4 - Lcm - Google Patents

Abstract

Grape Seeds Applications in drilling fluids Abstract In the Oil and Gas industry the drilling fluid being used has several important functions in order to mitigate problematic scenarios down hole while drilling. Some scenarios of concern are sub-surface lost circulation due to down hole permeable formations and seepage losses. Inclusive of this "Torque and Drag" affecting the capability of the rig surface equipment, down hole "Stick and Slip" which has a direct impact on bottom hole assembly performance and Differential sticking tendencies all contribute to the successfulness of the desired well being drilled. All of these factors can be mitigated through utilising the correct methodology of the drilling fluid and any additives therein. This document focuses on the benefits of introducing grape seeds in to the drilling medium in order to mitigate the previously mentioned areas of concern as well as incorporating grape seeds in to the induced fracturing process. Grape seeds are a by-product of the wine producing industry which are bi-degradable and environmentally friendly.

Description

EDITORIAL NOTE 2013100002 The description pages are pages 1, 2, 4, 6 and 8 The drawings pages are pages 3, 5 and 7 Claims are contained on page 9 The abstract is page numbered page 10 1 Grape Seeds Applications in drilling fluids Inventors Mr Brendon O'Toole Snr and Jnr 40 Cairnaquheen Gardens, Aberdeen. AB1O 6SA Scotland, UK & Mr James Victor Jones PO Box 146 Birdwood, 5234 South Australia 2 Statement of Invention - 1 " Application 1. Using Grape Seeds as an LCM Additive In the oil and gas industry "Lost Circulation Material" otherwise known as LCM has been utilised almost since the beginning of Oil or Gas extraction. Several problems are encountered while drilling which encapsulate ( not limited too ) the total or partial loss of the drilling fluid in to permeable zones and seepage losses through micro fractures. LCM is a composition of material which is used as a bridging or sealing agent to prevent fluid loss across these permeable or seepage zones and re-establish circulation returns at surface. One method in mitigating fluid losses is by incorporating ground up grape seeds in the range of 10 to 750 microns with a wetting additive, viscosifier and a activator or flocculant. The ground up grape seeds can be utilised as part of the LCM composition in fine, medium or course. This composition is dictated by the extent of the loss zone needing to be isolated. This method of ground up grape seeds can be used in conjunction with any plant such like material including not limited too ) Black Wallnut or other nut hulls, cotton seeds, corn cobs or rice fractions. Water absorbent polymers, swellable fibers or friction reducing material can also be part of this combination. The desired LCM incorporating the grape seeds composition can be added to the drilling fluid in a pill like form or on a continuous basis depending on the loss type and severity. Grape seeds are biodegradable and environmentally friendly. This can be better illustrated in diagram 1 on the next page: 4 Statement of Invention - 2 nd Application 2.0 Using LCM Seeds as a Torque and Drag Reducing Agent and to mitigate differential sticking As well as utilising grape seeds as a form of LCM in the drilling fluid, other applications are also available. While drilling surface torque and drag, down hole stick slip and differential sticking can also be a problem. Torque and Drag is limited to the rotational and pulling capability of the rig or working unit. This sometimes can result in not being able to drill and reach the required oil or gas zone. Alternatives due to this reason have to be made to change the rig specifications, well design or surface location which can be very expensive and even made the target reservoir uneconomical. Stick and slip can also be a deciding factor on the Bottom Hole Assemblies ( BHA ) capabilities while drilling. In this scenario the BHA components while drilling can experience severe torque in certain sections which if left untreated could result in the BHA parting. Again resulting in serious expense to the overall well cost. Differential sticking is also another main cause of concern in the drilling operation. While drilling if the drill string is left in the stationary position for prolonged periods of time, for example when making a connection. If the permeable zone in contact with the drill string is at a lower hydrostatic pressure, after only a few minutes differential sticking can start to take place. This can result in the drill string being stuck in some cases being completely lost down hole. the well The speed at which this occurs is dependent on the time the string is stationary for and the surface area of the drill string which is in contact with this permeable low pressure zone. Here in all these scenarios, the Grape seeds can be injected down the drilling string out the bit and circulated back up the wellbore to surface. The seeds will reduce the surface area of the drill string acting on the formation. This will assist in reducing torque and drag at surface, stick and slip down hole and the speed of which differential sticking takes place. These benefits will improve down hole drilling performance ( Rate of Penetration ) and mitigate BHA failure and differential sticking tendencies. Specifically for Extended Reach Drilling or Wells containing long horizontal sections. This can be better illustrated in diagram 2 on the next page.

6 Statement of Invention - 3 rd Application 3.0 Using Grape Seeds in to the Induced Fracturing Process Another application where grape seeds can be encompassed is as a proppant in the reservoir fracture and cleaning process. In impermeable formations where hydrocarbons are present. Fractures are induced in desired productions zones in order to extract the Hydrocarbons. Once the fractures have been achieved a medium is injected down hole to ensure the fractures remain open. This allows production of this zone to take place. The fractures can either be caused by means of explosives down hole or by the hydraulic medium itself - in either case this is known as induced fracturing. Regardless of which method is being utilised the grape seeds are injected in to the induced fractures which keep them open and enable the formation to be more permeable. The well is then clean out in order to remove any unwanted down hole debris which is then brought on to production. This process can implemented several times across the desired productive interval as dictated by the Oil and Gas Operator. This can be better illustrated in diagram 3 on the next page.

8 Advantages of using Grape Seeds in the drilling fluid 1. Grape seeds are cheap, biodegradable and environmentally friendly 2. Grape seeds can be grounded up to the required mesh size to obtain the correct LCM concentration needed to assist in curing the losses. 3. Grape seeds are recyclable and reusable, they can be collected at surface and re-injected down hole several times as needed 4. Grape seeds have a buoyancy factor heavier than water, so they can also be used as a weighting agent. 5. Grape seeds due to their natural size and shape can be used to reduce the surface area of the drill string and BHA in contact with the wellbore wall - thereby reducing surface torque and drag, stick and slip as well as differential sticking down hole. 6. Grape seeds can be used to hold open induced fractures without harming the environment. 7. Grape seeds can easily be injected through bottom hole assemblies without plugging up or damaging the down hole equipment.

Claims (4)

1. One method in mitigating fluid losses is by incorporating ground up grape seeds in with a wetting additive, viscosifier and a activator or flocculant, the ground up grape seeds can be utilised as part of the Lost Circulation Material composition in fine, medium or course, this composition is dictated by the extent of the loss zone needing to be isolated, this method of ground up grape seeds can be used in conjunction with any plant such like material including Black Wallnut or other Nut Hulls, Cotton seeds, Corn Cobs or Rice Fractions, Water absorbent polymers, swellable fibers or friction reducing material can also be part of this combination, The desired Lost Circulation Material incorporating the grape seeds composition can be added to the drilling fluid in a pill like form or on a continuous basis depending on the loss type and severity, Grape seeds have a buoyancy factor greater than water and could also be used as a weighting agent, Grape seeds can be injected down the drilling string out the bit and circulated back up the wellbore to surface, The seeds will reduce the surface area of the drill string acting on the wellbore walls, This will assist in reducing torque and drag at surface, stick and slip down hole and the speed of which differential sticking takes place will be reduced, These benefits will improve down hole drilling performance ( Rate of Penetration ) and mitigate bottom hole assembly failure and differential sticking tendencies, the grape seeds can also be injected in to induced fractures which keep them open and enable the formation to be more permeable which will improve production

2. Grape seeds are biodegradable and environmentally friendly

3. Grape seeds are recyclable and reusable, they can be collected at surface and re-injected down hole several times as needed

4. Grape seeds can easily be injected through bottom hole assemblies without plugging up or damaging the down hole equipment.