Abstract: A method for performing operations in a well comprises sensing a condition at, adjacent, or within a wellhead arrangement located at an opening of the well and performing a safety procedure in response to the sensed condition to improve the safety of the well operations. The method may comprise sensing the condition when a tool is located at, adjacent to, or within the wellhead arrangement. The sensed condition may be associated with a status of the tool. The sensed condition may be associated with an emission, field or signal transmitted to and/or from the tool, extending to and/or from the tool, and/or coupled to and/or from the tool. Performing the safety procedure may comprise controlling a position or status of the tool or controlling an environment at, adjacent to, or within the wellhead arrangement.

Abstract: A wellbore communication system (1) comprises a downhole tool (2) having a downhole transmitter (40), a sensing element (22, 122, 222, . . . , 1022) located at surface and coupled to a surface receiver (44), and an insulated slickline (6, 106, 206, . . . , 1006) having an electrically conductive core surrounded by an insulating coating. The slickline is attached to the downhole tool and coupled to the downhole transmitter. The sensing element is capacitively coupled to the slickline so as to permit movement of the slickline relative thereto and so as to an electric field to extend from the core of the slickline through the insulating coating to the sensing element for transmission of information from the downhole transmitter to the surface receiver via the slickline and the sensing element.

Abstract: A communication system, comprises a composite slickline including an electrical conductor surrounded by an electrically insulating structural material, a downhole tool; and a sensing element. The composite slickline is mechanically and electrically coupled to the downhole tool and extends from the downhole tool to the sensing element. The composite slickline and the sensing element are capacitively coupled so as to permit relative movement therebetween and so as to permit an electric field to extend from the electrical conductor of the composite slickline to the sensing element through the electrically insulating structural material of the composite slickline for the transmission of an electrical and/or an electromagnetic signal between the downhole tool and the sensing element via the composite slickline.

Abstract: A method for use in measuring a property of an environment or an object in, or adjacent to, an elongated space (10), comprises unspooling and/or spooling a line (6) attached to a tool (4) so as to move the tool along an elongated space. The method may comprise using the tool to measure a property of an environment or an object in, or adjacent to, an elongated space during movement of the tool along the elongated space. The method may comprise, determining an acceleration of the line, measuring an acceleration of the tool along the elongated space, and controlling damping of the movement of the tool along the elongated space according to the measured acceleration of the tool and the determined acceleration of the line. The elongated space may be located downhole or may be defined in, or adjacent to, an oil or gas well.

Abstract: A wireline apparatus comprises a sheave for accommodating a wireline and a sheave mounting configured for coupling to a wireline stuffing box. The apparatus includes a sensor for measuring at least one of wireline tension and deployed wireline length at the sheave.