A method to manipulate a well, comprising: - providing a pressure sensor in the well; - providing an apparatus in a well below an annular sealing device, the annular sealing device engaging with an inner face of casing or wellbore in the well, and being at least 100m below a surface of the well, - providing a connector (16, 50) for connecting the apparatus to the annular sealing device, the connector being above the apparatus and below the annular sealing device; the apparatus comprising: - a container having a volume of at least 50 litres; - a port to allow pressure and fluid communication between an inside and an outside of the container; - a mechanical valve assembly having a valve member adapted to move to selectively allow or resist fluid entry into at least a portion of the container, via the port; - a control mechanism (64, 66) to control the mechanical valve assembly, comprising a communication device configured to receive a control signal for moving the valve member; - sealing the container at the surface, and then deploying it into the well such that the apparatus moves from the surface into the well below the annular sealing device with the container sealed; - the pressure in at least a portion of said inside of the container being less than said outside of the container for at least one minute; - sending a control signal from above the annular sealing device to the communication device at least in part by a wireless control signal transmitted in at least one of the following forms: electromagnetic, acoustic, inductively coupled tubulars and coded pressure pulsing; - moving the valve member in response to said control signal to allow fluid to enter the container; and, - drawing in at least 5 I of fluid into the container. - providing a pressure sensor in the well; - providing an apparatus in a well below an annular sealing device, the annular sealing device engaging with an inner face of casing or wellbore in the well, and being at least 100m below a surface of the well, - providing a connector (16, 50) for connecting the apparatus to the annular sealing device, the connector being above the apparatus and below the annular sealing device; - a container having a volume of at least 50 litres; - a port to allow pressure and fluid communication between an inside and an outside of the container; - a mechanical valve assembly having a valve member adapted to move to selectively allow or resist fluid entry into at least a portion of the container, via the port; - a control mechanism (64, 66) to control the mechanical valve assembly, comprising a communication device configured to receive a control signal for moving the valve member; - sealing the container at the surface, and then deploying it into the well such that the apparatus moves from the surface into the well below the annular sealing device with the container sealed; - the pressure in at least a portion of said inside of the container being less than said outside of the container for at least one minute; - sending a control signal from above the annular sealing device to the communication device at least in part by a wireless control signal transmitted in at least one of the following forms: electromagnetic, acoustic, inductively coupled tubulars and coded pressure pulsing; - moving the valve member in response to said control signal to allow fluid to enter the container; and, - drawing in at least 5 I of fluid into the container. - moving the valve member in response to said control signal to allow fluid to enter the container; and, - drawing in at least 5 I of fluid into the container.