Abstract: A method of managing lost returns in a wellbore includes contacting a filter cake with a treating fluid to remove metallic weighting agents from the filter cake, wherein the filter cake is disposed on a face of a formation fracture in the wellbore. The method also includes contacting the filter cake with a proppant slurry, wherein the proppant slurry contacts the filter cake concurrently with the treating fluid or after the treating fluid contacts the filter cake. This method may include increasing the filter cake permeability and may utilize a barite removal agent, such as a chelation agent. At least one related wellbore management method creates a fracture in the wellbore and props open the fracture to increase wellbore integrity to utilize higher weight drilling fluids and prevent fractures from forming further down the wellbore.

Abstract: A process for drilling a well or a portion of a well capable of providing a generally constant interior wall diameter (monobore) and does not require installation of any liner or steel casing. The process comprises circulating settable material into the borehole wherein the settable material sets on at least a portion of the interior wall of the borehole to create a liner along the wall of the borehole and removing excess settable material out of the borehole.

Abstract: Methods for installing tubulars (for example, conduits, casing or liners) into a highly deviated wellbore are disclosed. In a first embodiment, the method comprises a) drilling the well to the planned total depth of the interval, b) placing a first fluid into the wellbore below a prescribed measured depth in the high-angle portion of the wellbore, said first fluid having a density that causes the portion of the tubular that extends into the first fluid to become substantially neutrally buoyant, c) placing a second fluid into the wellbore above the prescribed measured depth, said second fluid having a density less than said first fluid, d) plugging the distal portion of the tubular with a lower plug (or check valve) and an upper plug, e) as the tubular is run into the wellbore, placing a lightweight fluid into the plugged section of tubular and a heavy fluid above the plugged section of tubular, and f) running the tubular into the wellbore to the planned total depth.

Abstract: Methods and apparatus for mitigating the effects of vibration of various tools, such as those used downhole, by utilizing a vibration isolation device that incorporates Shape Memory Alloys (SMAs). For instance, in some embodiments, a vibration isolation device may be designed and deployed in a manner such that, when a vibration isolation device is operated in an expected manner, the force on the SMAs from static loading is sufficient to induce partial phase transformation between the austenite and martensite phases. This partial phase transformation may result in a reduced stiffness of the vibration isolation device in comparison to a tool in either a full austenite phase or full martensite phase.

Abstract: The present invention is a method of estimating formation properties by analyzing acoustic waves that are emitted from and received by a bottom hole assembly. A bottom hole assembly may be deployed in a borehole to estimate formation properties. From the bottom hole assembly, a source signal may be emitted and at least one signal may be received by one or more receivers in the bottom hole assembly. Analysis of the frequency dependent characteristics of the received signal allows the estimation of the formation properties of interest, including pore pressure. The formation properties of interest may be used to monitor a wellbore pressure safety margin and to optimize drilling mud weight.

Abstract: A process for drilling a well or a portion of a well capable of providing a generally constant interior wall diameter (monobore) and does not require installation of any liner or steel casing. The process comprises circulating settable material into the borehole wherein the settable material sets on at least a portion of the interior wall of the borehole to create a liner along the wall of the borehole and removing excess settable material out of the borehole.

Abstract: The present invention is a method for improving well cementing. A fluid such as drilling mud or preflush fluid is oscillated in the annulus prior to introduction of cement slurry into the annular interval to be cemented. The fluid is oscillated by changing its direction of flow at least twice. The oscillatory flow of the fluid flushes gelled drilling mud and filter cake from the annulus more effectively than conventional unidirectional flow. Following the oscillatory phase, cement slurry is pumped into the annular interval to be cemented, thus displacing the fluid, and is allowed to set. The fluid can be oscillated in the annulus either before or after the cement slurry is introduced into the casing. A selective check valve is also described which permits all fluids to flow in the forward direction out of the casing and into the annulus and which permits all fluids other than cement slurry to flow in the reverse direction out of the annulus and into the casing.

Abstract: An improvement to a centralizer that may reduce the torque required to rotate a casing in a borehole during primary cementing is disclosed. In a first embodiment, the improvement is adapted to a bow spring type centralizer having intermediate fixed and slidable sleeves with each sleeve circumscribed by an end band. The end bands are connected to each other by a plurality of bow springs. The improvement includes interposing a sleeve bearing between each end band and its respective intermediate sleeve. The sleeve bearings may be attached to the intermediate sleeves to permit their rotation with the casing relative to the stationary end bands and bow springs. Alternatively, the intermediate sleeves may be eliminated and the sleeve bearings interposed directly between the outer surface of the casing and inner surfaces of their respective end bands.