This disclosure relates to techniques for determining a dissociation constant of a reservoir that includes methane hydrate and generating a methane hydrate production output that may be used to inform certain decisions related to processing a reservoir that includes the methane hydrate. In some embodiments, the techniques may include determining the dissociation constant using multiple pressures measured at different flowrates at time points from within a wellbore.

An intra-layer reinforcement method, and a consolidation and reconstruction simulation experiment system and an evaluation method for a gas hydrate formation are provided. In the intra-layer reinforcement method, the formation reconstruction and fracturing grouting reinforcement technologies are combined; a fracturing grouting process is adopted to create fractures in the gas hydrate formation; and a consolidation liquid enters the fractures and penetrates into the formation through a pressure difference to form a reinforcement with a ribbed slab structure and a specified strength and permeability, which supports the formation to achieve collapse prevention and sand prevention. A specific consolidation and reconstruction simulation experiment system is adopted, where the necessary conditions for the generation and decomposition of a hydrate are tested, and the fracturing, formation consolidation, and cementing experiments are simulated to study a rational exploitation method of a gas hydrate, thereby solving the problem of sand production of the hydrate layer.

A device and a method for experimental exploitation of natural gas hydrates in full-sized production wells are provided. The device includes a full-diameter well, and the full-diameter well includes a heating circulation tube, a temperature sensor tube, an upper sealing unit and a lower sealing unit. Perforations are provided along a body of the full-diameter well. A reactor includes an upper cover, a lower cover, and a reactor body. The method is conducted by using the device and the reactor. The device and method allow simulation of sand-control wellbores in actual exploitation of natural gas hydrates, and realize horizontal and vertical sand-control experiments.

The present invention discloses a sand control device for marine hydrate production, which comprises a top motor, a bottom motor, and an inner-layer sand control cylinder, an outer-layer sand control cylinder and an outer-layer sand control screen coaxially arranged from inside to outside, wherein the top motor and bottom motor are configured to control the inner-layer sand control cylinder and the outer-layer sand control cylinder to rotate reversely, and wherein a plurality of sand retaining balls are provided between the inner-layer sand control cylinder and the outer-layer sand control cylinder and between the outer-layer sand control cylinder and the outer-layer sand control screen. According to the present invention, the arrangement of the inner-layer sand control cylinder and the outer-layer sand control cylinder rotating reversely can effectively prevent formation sand from accumulating on the surface of a sand control screen pipe and blocking the sand control screen pipe.

A divisible device and a method for sand production and sand control experiment for natural gas hydrate exploitation. The experimental device includes a reactor system, a feeding system, a separation and measurement system, a water-bath jacket system, a support and safety system, and a software recording and analyzing system. In the reactor system, the reactor units can be combined in different ways depending on the experimental conditions and purposes. The reactor units include: left/right reactor units, secondary reactor units, central reactor units, and caps. The combination of a left/right reactor unit with a cap gives a hydrate formation reactor without sand control screens. Combining the left/right reactor unit, secondary left/right reactor units and central reactor units with other accessories allows the reactor system to carry out the simulation experiments with either zero, one, or two view zones, and with either one or two wells.

The present invention relates to a natural gas hydrate pressure-retaining corer, which includes an outer tube assembly and an inner tube assembly installed inside the outer tube assembly. The inner tube assembly includes an inner tube assembly a and an inner tube assembly b. The inner tube assembly a includes a spearhead, a latching device, a suspension plug, a hydraulic piston tube, a piston short limit short section, a limit copper pin, a sealing head, a middle tube, a weight tube drive mechanism and a pressure-retaining ball valve closing sealing mechanism which are sequentially connected from top to bottom. The inner tube assembly b includes a piston compensation balance mechanism, a single-action mechanism, an accumulator mechanism, a sealing mechanism and a core barrel connected sequentially from top to bottom.

The present invention discloses a silty marine natural gas hydrate gravel stimulation mining method and a mining device. The mining method appropriately relaxes the sand retention accuracy of a wellbore, so that the fine sand and muddy components of the stratum can flow into the wellbore, and after a certain period of production, the coarse gravels are injected into the extra-pipe stratum of the production well to fill the deficit caused by the production of the fine components of the stratum and the hydrates, and then the well is opened for production. The method achieves the triple objectives of improving the productivity of the silty reservoir, preventing the large-area deficit in the stratum and extending the effective period of the sand retention of the wellbore, by way of the alternation of the rounds of the gravel injection and the hydrate reservoir fluid extraction.

A high-efficiency yield-increasing exploitation method for natural gas hydrates includes steps of drilling of natural gas hydrate reservoirs along horizontal wells, seepage increasing by fracturing for fracture forming and stability improvement by grouting in the natural gas hydrate reservoirs, and yield improvement by combined exploitation of depressurization of the horizontal wells and heat injection; according to the present invention, drilling time is shortened by rapid drilling along the horizontal wells, the permeability of the reservoirs can be effectively improved by fracturing for fracture forming, the stability of the reservoirs can be improved by injecting foam cement slurry into the reservoirs, and the yield of the natural gas hydrates can be improved by the combined exploitation method of depressurization of the horizontal wells and heat injection.

A system for use in a wellbore that penetrates a subterranean formation, the system comprising: a wellbore; and a ball, wherein the ball performs one or more wellbore operations, and wherein the ball breaks apart into two or more pieces when a pressure is applied to the ball. A method of performing an operation in a wellbore, the method comprising: introducing a ball into the wellbore; causing or allowing the ball to perform at least one wellbore operation; and causing the ball to break into two or more pieces after performing the at least one wellbore operation. The ball can also perform more than one wellbore operation. The ball can also contain a core.

In some examples, a method performed by a drilling rig control center, includes receiving raw data for a first time segment, the raw data related to a drilling operation. In addition, the method includes deriving first drilling state measurements based on the raw data of the first time segment. Further, the method includes deriving first formation state measurements based on the raw data of the first time segment. The method also includes correlating the first derived drilling and formation state measurements of the first time segment with a second derived drilling and formation state measurements of a second time segment. Still further, the method includes generating a control response based on the correlation.