A method to manipulate a well comprising providing an apparatus (60) in a well (14) below a packer (22) or other annular sealing device, the apparatus comprising a container (68) having a volume of gas which is sealed at the surface and nm into the well, such that the pressure in the container (68) is at a lower pressure than the surrounding well. When the apparatus is below the packer, a wireless control signal, is sent to operate a valve assembly (62) to selectively allow fluid to enter the container whereby at least 50 litres of fluid is drawn into the container. In this way, the apparatus can be used independent of perforating guns, to clear perforations or other areas in the well or may be used for a variety of tests such as an interval test, drawdown test or a connectivity test such as a pulse or interference test.

Systems and processes for subsea marine managed pressure operations. One system includes a modified riser joint configured to fluidly connect inline with one or more riser joints. The modified riser joint and the one or more riser joints are connected to form a riser connecting a floating vessel with a wellhead. The system further includes a subsea pressure management sub-system configured to be operatively and fluidly connected to the modified riser joint at a subsea location.

The invention provides well control system for a riser. The well control system comprises a riser assembly and at least one flow meter. The at least one flow meter is configured to be mounted on the riser.

The invention concerns a computer implemented method for underbalanced drilling. In one embodiment, the method includes determining a plurality of gas injection rate versus bottom hole pressure curves for a plurality of liquid injection rates for a specified minimum and maximum gas injection rate and a minimum and maximum liquid injection rate. Next, the method determines a set of four interception curves including a minimum motor equivalent liquid rate interception curve, a minimum vertical liquid velocity intercept curve, a minimum horizontal liquid velocity intercept curve, and a maximum motor equivalent liquid rate intercept curve for a specified minimum and maximum mud motor rate range and a minimum horizontal and vertical annulus velocity.

A method for performing a drill stem test (DST) is disclosed. The method includes performing underbalanced drilling (UBD) of exploration wells to penetrate a target interval in a subterranean formation, where UBD is performed when a wellbore fluid pressure is less than a formation fluid pressure to allow a fluid flow from the target interval to surface during a drilling phase of the UBD, determining, based on the UBD of the exploration wells, a measure of the fluid flow from the target interval to the surface, obtaining, based on the UBD of the exploration wells, open hole logs of the exploration wells, where the open hole logs represent a reservoir property of the target interval, and selectively performing, based at least on the measure of the fluid flow and the open hole logs, the DST of the exploration wells.

A very light weight, noncompressible drilling fluid including a very light weight hydrocarbon base liquid, and a styrenic butadiene diblock copolymer is heated to achieve excellent rheology including thixotropicity, making an effective drilling fluid with a density of 8 pounds per gallon or less. Densities as low as 4 pounds per gallon are achieved with the addition of glass bubbles. The glass bubbles may, but normally will not, exceed 50% by volume. A method of making the drilling fluid includes passing the light weight liquid and the copolymer through a cavitation device. The invention includes drilling and with and recirculating the fluid to maintain the desired density, viscosity and rheology by adjusting the ingredients accordingly. A method of managed pressure drilling employs the novel fluid, enabling control of drill pressure and physical properties of the fluid including equivalent circulating density.

Systems and methods include a method for providing an integrated advanced visualization tool for geosteering underbalanced coiled tubing drilling (UBCTD) operations. Drilling operation data is received from different sources in real time during a drilling operation. The drilling operation data includes geological formation information recorded during the drilling operation, micropalaeontological test results of the drilling operation, drilling parameters being used during the drilling operation, cumulative productivity index calculations, and reservoir pressure information of reservoirs encountered during the drilling operation. The drilling operation data is analyzed to correlate elements of the drilling operation data by time and cumulative depth. A graph is generated in real time that includes multiple plots correlated as a function of cumulative depth over time.

A downhole tool assembly for completing or cleaning a wellbore. The downhole tool assembly may include a perforation gun sub and a laser assembly sub. The perforation gun sub may be used to propagate a shockwave through one or more pre-existing perforations in a formation. The laser assembly sub may be used for treating perforations, e.g. treating the one or more pre-existing perforations. Depending on the parameters of the operation, the treating of the perforations may comprise changing the shape of the perforations and/or making the perforations wider, deeper, or otherwise adjusted.

Systems and processes for subsea marine managed pressure operations. One system includes a modified riser joint configured to fluidly connect inline with one or more riser joints. The modified riser joint and the one or more riser joints are connected to form a riser connecting a floating vessel with a wellhead. The system further includes a subsea pressure management sub-system configured to be operatively and fluidly connected to the modified riser joint at a subsea location.

A Drill-To-The-Limit (DTTL) drilling method variant to Managed Pressure Drilling (MPD) applies constant surface backpressure, whether the mud is circulating (choke valve open) or not (choke valve closed). Because of the constant application of surface backpressure, the DTTL method can use lighter mud weight that still has the cutting carrying ability to keep the borehole clean. The DTTL method identifies the weakest component of the pressure containment system, such as the fracture pressure of the formation or the casing shoe leak off test (LOT). With a higher pressure rated RCD, such as 5,000 psi (34,474 kPa) dynamic or working pressure and 10,000 psi (68,948 kPa) static pressure, the limitation will generally be the fracture pressure of the formation or the LOT. In the DTTL method, since surface backpressure is constantly applied, the pore pressure limitation of the conventional drilling window can be disregarded in developing the fluid and drilling programs.