Patent EA-002944-B1 (EA)
Title: Method of creating a wellbore
Inventor: COENEN JOSEF GUILLAUME CHRISTO
IPC: E21B23/14
Filed: 2000-05-30
Abstract: 1. A method of creating a wellbore in an earth formation, the wellbore including a first wellbore section and a second wellbore section penetrating a hydrocarbon fluid bearing zone of the earth formation, the method comprising - drilling the first wellbore section; - arranging a remotely controlled drilling device at a selected location in the first wellbore section, from which selected location the second wellbore section is to be drilled; - arranging a hydrocarbon fluid production conduit in the first wellbore section in sealing relationship with the wellbore wall, the conduit being provided with fluid flow control means and a fluid inlet in fluid communication with said selected location; - operating the drilling device to drill the second wellbore section whereby during drilling of the drilling device through the hydrocarbon fluid bearing zone, flow of hydrocarbon fluid from the second wellbore section into the production conduit is controlled by the fluid flow control means. 2. The method of claim 1, wherein arranging the drilling device in the first wellbore section comprises suspending the drilling device from the production conduit, and simultaneously lowering the production conduit and the drilling device into the first wellbore section. 3. The method of claim 2, wherein the first wellbore section is provided with a casing and the production conduit is at the lower end part thereof provided with an inflatable packer for sealing the conduit relative to the casing, and wherein the drilling device is releasably connected to said packer during simultaneous lowering of the production conduit and the drilling device into the first wellbore section. 4. The method of any one of claims 1-3, wherein the drilling device is operated by electric power, and the method further comprises lowering an electric conductor wire through the production conduit and connecting the conductor wire to the drilling device. 5. The method of claim 4, wherein the conductor wire is lowered through the production conduit by connecting a pump-down element to the wire and pumping the pump-down element through the production conduit. 6. The method of claim 4 or 5, wherein the drilling device is provided with means for measuring data on at least one of a formation characteristic, a wellbore characteristic, and a drilling characteristic, and wherein the method further comprises transmitting said data through the conductor wire to surface. 7. The method of any one of claims 1-6, wherein the drilling device comprises a front member including a drill bit, a rear member provided with retractable anchoring means for anchoring the rear member to the borehole wall, the front member and rear member being arranged in a telescoping relationship, and thrust means for thrusting the front member in telescoping outward direction relative to the rear member, and wherein the step of operating the drilling device includes anchoring the rear member to the borehole wall and inducing the thrust means to thrust the front member in telescoping outward direction relative to the rear member and against the borehole bottom. 8. The method of any one of claims 1-7, wherein the drilling device comprises a pump system having an inlet arranged to allow drill cuttings resulting from the drilling action of the drilling device to flow into the inlet, and an outlet arranged to discharge said drill cuttings into the wellbore behind the drilling device. 9. The method of claim 8, wherein said outlet is arranged a selected distance behind the drilling device and at a location in the wellbore section where a fluid is circulated through the wellbore, which fluid entrains the drill cuttings and transports the drill cuttings to surface. 10. The method substantially as described hereinbefore with reference to the drawings.