When drilling a 6,000 m vertical well, how accurate can you be in the finish location, is it mm, cm, m, or 10s of m?
“How accurate can you be?”How much money do you have? Wells can be drilled to intersect existing wellbore, for example in the case of a blowout like Macondo. In that case, you have steel in the ground to find, and proximity logs to run in the intercept well.So the location can be within cm, depending on the objective and budget.Surveying equipment is probably good enough to hit an abstract target within a meter. We generally drill directional wells with a 50–100 ft radius target at deeper depths than 6,000 ft. With controlled drilling, I’d say we are within 10 ft of the target more often than not. Usually there is not much value in being more precise because we are trying to hit something that is about the same size as the broad side of a barn. If it’s the size of a refrigerator, it’s just not a very big container. Precision drilling costs a lot because it is slower.I believe that vertical wells (without mud motors and downhole surveying) must have the inclination surveyed to show that the maximum deviation (dogleg) does not exceed 5 degrees.Now, worst case, if the entire wellbore was at 5 deg inclination from spud to TD and it were all the same direction (highly unlikely), then the bottom hole location would be ~522 ft from surface, if my trigonometry is right.It would be much more common for average inclination to be about 1 to 2 degrees. Worst case 100–200 ft from surface, if all the deviation is in one direction. That’s if you’re drilling a conventional vertical well with no directional control.
How far can you drill using horizontal drilling technology?
Wells 6 to 8 miles long (ca 9 to 11 km) are currently branded as 'the longest horizontal wells'. How far it is technically possible to drill will probably change as technology progresses. An example is the Reelwell drilling method, which supply force on the drill bit via hydraulics instead of the drillstring, making longer horizontal wells possible. The company states [1] that the present limit for extended reach drilling (the industry term for long horizontal wells) is 12 km (7.4 miles) but that their technology should be able to push this to 20 km (12.4 miles) [1] http://www.reelwell.com/reelwell...
Why is directional drilling introduced?
Why is directional drilling introduced?Historically directional drilling was introduced to deviate wells around an obstruction or fish in the wellbore. Didn't really care where the wellbore went just wanted to get around the fish and then back to vertical. Inclination only measurements, direction not really a concernDirectional motors were one of the first 3D steering the wells and this was an expensive proposition. Targets were typically simply a formation. Hit the formation and this was considered a success. The more vertical a well was enabled easier lifetime completions (rod wear for pumped wells) and other metrics were considered and attempts to put a net present value on those metrics allowed the expense of directionally drilling a well.Offshore drilling was a boon to directional drilling. On land drilling up a field with vertical wells makes sense as the cost of an additional location is relatively small. Offshore the cost of an additional platform is significant, therefore allowing significant expense to be spent drilling multiple locations from one platform. This expertise although expensive was economically justifiable in certain situations. as the technology matured and became more reliable and therefore cheaper it was use became more popular. Smaller targets and multiple targets per wellbore became achievable.Realtime geosteering wells became a service decades ago that became available with advances in MWD telemetry and sensors. You really couldn’t do the horizontal shale plays without it.
Needing to run a water line through a creek...?
I have to run 2100 ft of water line, about 12 feet of which will be through a creek bed. I will likely be hiring this job out, but I want to know what options there are for digging/breaking up the creek bed. I don't know what type of rock it is that lines the bottom of the bed, but it there is no loose rock to dig through, so the solid rock needs to be broken. Any information of links will be appreciated, thanks.
What are things that can cause delays while working on the rig for a drilling contractor?
Almost everything can cause delay during the drilling process especially if the drilling operation is not well programmed. that’s why some contractors use drilling program. The drilling program will be used as a guide to help you during the drilling operation. It will provide you with the cost estimation) of the drilling operation and the list of service companies (water, cement, logging), and arrange the exact time to provide with their service. This will save the company cost and time and avoid delays. With the lithology information, you will be able to design the drilling program, casing program, with knowledge of formation pore pressure and fracture gradient we can select the right mud weights and avoid kick etc. There are other factors that can cause delays that are impossible to control e.g natural disasters and others that can be avoided but sometimes difficult, like a stuck pipe, or when some unwanted object falls into the borewell, and uncontrolled kick (blowout). Yes, these can cause serious delay to the drilling process.
What is the difference between driller and drilling engineer?
Thanks for the A2A.Drilling a well is a very complex process. It requires a lot of planning and continuos risk-management. A Well Plan is usually the map that describes how it been planned to happen -i.e. to which depth you are going to drill to before you stop to set casing, what's the mud weight, how many RPM's and WOB (Weight On Bit) you are going to use, etc. The Well Plan is written by drilling engineers with input from geologists, petrophysics and professionals from other disciplines. The well is drilled using a drilling rig, usually a derrick with bunch of equipment to help turn the drilling bit or preventing the well from blowing-out-. The driller is the one executing the instructions and the leader on the rig floor (the derrick). So he will actually apply the weight on the bit, rotate at the required RPMs, and maintain an eye pn everyone and everything on the rig floor. They are experienced professionals who know how and when react in front of any contingency or events not included in the Well Plan.I believe drilling engineers gain a lot of insight from talking to drillers and many of them have actually spent valuable time on the rig floor as drillers.
What is a successful drilling company?
A successful drilling company is one that takes safety seriously. A very real problem in today's drilling world is putting time of the outmost importance. If you work in drilling, operations managment or some position in time utilization or optimization, I want you to read this and understand it well.To work on a drilling rig requires a lot of heart, skill, strength and most importantly brains. Each and every employee envolved in the day to day tasks is an important cog in a gear. One cog not in place or missing brings the big operation to a halt. To keep operations running smoothly takes confidence in yourself and your crews ability to safely perform a task through experience and mentoring jr employees is key. The word here… Patience. In an industry where companies try to push you to outperform, speed up or optimize performance, it is easy to overlook that everybody works productivly and safely. Safety is discussed daily, pre task and while performing duties. Humans are humans, some smarter, faster and stronger than others. Are able to out perform others in one area or another. So to understand this, may make you redirect your thinking on how you approach safety. The best way to speed up an operation is by planning ahead and staying in control of your day. Safety is success, success is moving forward, moving forward promotes well being and accomplishment. If your finding an operation is lagging behind, it's usually due to lack of safety. Lack of safety is usually undertrained crews. Thats a successful drilling company. A successful oil company now that's a different topic.