The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 09, 1986
Filed:
Jul. 05, 1985
George F Gehrig, Houston, TX (US);
Jerry M Speers, Houston, TX (US);
Exxon Production Research Co., Houston, TX (US);
Abstract
A method and apparatus for establishing the rate at which fluid is transferred between an offshore well 16 and the formations 20 surrounding the well 16 in the course of drilling the well 16 from a floating drilling rig 14. A drilling fluid handling system 31 is used to inject drilling fluid into the well 16. A marine riser 22 extending from the sea bottom 18 to the rig 14 is provided to return the drilling fluid to the rig 14. The riser 22 is provided with a slip joint 26 to accommodate wave induced heave of the rig 14. Inflow and outflow flowmeters 42,44 are provided to monitor the rates at which drilling fluid is injected into the well 16 and returned to the rig 14. The return flow rate signal is filtered to mitigate the cyclical variations resulting from extension and contraction of the slip joint 26. A signal processing system 46 is provided to maintain the time constant applied in the filtering process at an optimum level as the rate and magnitude of rig heave varies with time. The input and filtered output signals are combined to yield a differential flow signal which is compared to a preselected alarm limit to determine if excessive fluid transfer between the well 16 and surrounding formations 20 is occurring.