4 results about "Underbalanced drilling" patented technology

A method for underbalanced drilling includes drilling into a subterranean geological formation to form a wellbore therein, injecting a foaming agent into the wellbore during drilling at a wellbore pressure that is below a pore pressure of the subterranean geological formation, and transporting drill cuttings formed by the drilling away from the drilling surface in the foam. The foaming agent forms a foam in the wellbore at a drilling surface at a bottom of the wellbore. The foaming agent is an aqueous solution including an ammonium alcohol ether sulfate surfactant.

This invention discloses a method and apparatus for reducing the bottom-hole circulating temperature of deep shale gas horizontal wells, relating to the field of drilling engineering technology. It addresses the technical problem of unsatisfactory cooling effects when using existing surface cooling methods. The method includes the following steps: Step S1: Obtain the three-pressure profile of the well to be drilled and obtain the underpressure value range; Step S2: Determine the underbalanced drilling process based on the underpressure value range; Step S3: Obtain first relationship information and predict the bottom-hole circulating temperature of the well to be drilled. Based on the bottom-hole circulating temperature, the first relationship information, the three-pressure profile, and the underbalanced drilling process, optimize the drilling fluid density in the drilling process. This invention can effectively reduce the bottom-hole circulating temperature during deep shale gas drilling, ensure stable instrument operation, reduce the number of tripping operations, and guarantee efficient drilling of horizontal wells.

A method of underbalanced drilling includes drilling into a subterranean geological formation to form a wellbore and injecting a foaming agent into the wellbore during drilling at a wellbore pressure that is below a pore pressure of the subterranean geological formation. The foaming agent forms a foam in the wellbore at a drilling surface at a bottom of the wellbore and transports drill cuttings formed by the drilling away from the drilling surface in the foam. The foaming agent is an aqueous solution including a gemini amphiphile dicationic surfactant having a linker and a lipophilic tail.

The present disclosure relates to systems and methods for real-time calculations of a productivity index and a rate-integral productivity index of a well in underbalance drilling. The systems and methods use real-time data received from the well to calculate the productivity index and the rate-integral productivity index of the well. The systems and methods use the productivity index and the rate-integral productivity index to generate visualizations of the well and provide recommendations for the well.