The systems and method described in this specification relate to at least partially restoring carbonate core samples. The systems and methods include extracting a carbonate core sample from a subterranean formation. The extracted carbonate core sample is inserted into a core flooding test machine. A first brine permeability of the extracted carbonate core sample is measured. A fluid is pumped through the extracted carbonate core sample to flood the carbonate core sample. The fluid includes at least one of a high-molecular weight polymer solution and a gel particle solution. The systems and methods include at least partially restoring the porosity and the brine permeability of the flooded carbonate core sample by pumping an oxidizing solution through the carbonate core sample and heating the carbonate core sample to a temperature of at least 60° C. after pumping the oxidizing solution through the carbonate core sample.

An application method of a device for accurately evaluating the vertical content distribution of an undersea hydrate reservoir includes the following steps: assembling the device into a whole and screwing it into an undersea well; activating natural gas hydrates to produce gaseous substances; opening a directional guide channel corresponding to a thermal excitation system in a working state in S2, so that gaseous natural gas hydrates generated in this horizon enter a screw-in long sleeve through the directional guide channel; collecting, by a gas collection system, the gaseous natural gas hydrates; analyzing and recording components and contents in a box by an optical ranging unit and a resistivity unit; repeating S4 and S5 till the end of one collection cycle; and performing data processing and analysis. In this way, accurate evaluation of the vertical content distribution of undersea hydrates is realized.

A fluid sampling and measuring assembly has: a sampling and measuring module configured to sample and analyse a fluid sample; a picking module configured to contain the fluid sample; at least one navigation module configured to navigate in the body of water; and at least one interface module configured to hydraulically connect a sampling station, the sampling and measuring module and the picking module. The sampling and measuring module and the picking module are configured to be mechanically and hydraulically coupled to each other and to the sampling station to take and analyse the fluid sample and the picking module is configured to be coupled to the navigation module to transfer the fluid sample to an analysis laboratory.

A method for determining a presence of reservoired hydrocarbons having a hydrocarbon seep involves locating a hydrocarbon seep at a seabed location where hydrocarbon is actively flowing out of the seabed. Temporally spaced molecular compositions of the hydrocarbon seep are determined. When a temporal variance between the molecular compositions falls within a predetermined temporal tolerance, the hydrocarbon seep is classified as being indicative of the presence of reservoired hydrocarbons. A unique identifier is assigned to the reservoired hydrocarbons.

Methods of marine to borehole measurement may include dispersing one or more borehole receivers in one or more boreholes; distributing one or more marine receivers in marine water at a seabed; immersing an electromagnetic dipole source in the marine water above the seabed; energizing the electromagnetic dipole source; measuring one or more borehole signal measurements using the one or more borehole receivers and one or more seabed signal measurements using the one or more marine receivers; and determining a three-dimensional property distribution of a reservoir of interest by processing the one or more borehole signal measurements and the one or more seabed signal measurements.

Apparatus for monitoring the quality of gas in a process stream at a subsea location comprises: a container for permanent installation at the location; one or more devices for analysing gas quality, said devices being located in the container; and means for supplying a sample of gas from the process stream to the said one or more devices; wherein the pressure within the container is maintained at or near to atmospheric pressure. The invention also extends to a method of monitoring the quality of gas in a process stream at a subsea location.

Embodiments herein describe apparatus, systems and methods adapted to monitor underwater wells, boreholes, drill holes, etc. (subsea wells). Depending on embodiment, the apparatus, systems and methods can be configured to capture sensor readings and/or to monitor status of a target subsea wells.

An application method of a device for accurately evaluating the vertical content distribution of an undersea hydrate reservoir includes the following steps: assembling the device into a whole and screwing it into an undersea well; activating natural gas hydrates to produce gaseous substances; opening a directional guide channel corresponding to a thermal excitation system in a working state in S2, so that gaseous natural gas hydrates generated in this horizon enter a screw-in long sleeve through the directional guide channel; collecting, by a gas collection system, the gaseous natural gas hydrates; analyzing and recording components and contents in a box by an optical ranging unit and a resistivity unit; repeating S4 and S5 till the end of one collection cycle; and performing data processing and analysis. In this way, accurate evaluation of the vertical content distribution of undersea hydrates is realized.

Provided herein are systems and methods for generating reservoir models including the SOC nature of the Earth's crust. The methods employ seismic emission tomography (SET) to generate three dimensional models of a formation providing permeability without the need for traditional reservoir modeling techniques and allowing for the identification of naturally-occurring permeability pathways that provide accurate and precise locations for the efficient recovery of hydrocarbons or other fluids.

An apparatus and system for accessing a flow system (such as a subsea tree) in a subsea oil and gas production system, and method of use. The apparatus comprises a body defining a conduit therethrough and a first connector for connecting the body to the flow system. A second connector is configured for connecting the body to an intervention apparatus, such as an injection or sampling equipment. In use, the conduit provides an intervention path from the intervention apparatus to the flow system. Aspects of the invention relate to combined injection and sampling units, and have particular application to well scale squeeze operations.