Abstract: Wellbore fluid compositions containing a base fluid; at least one synthetic fiber; and a particulate solid are provided. In another aspect, methods of reducing loss of wellbore fluid into and strengthening of a formation are provided, including: introducing into the wellbore a fluid composition comprising one or more synthetic fibers and one or more particulate solids.

Abstract: Wellbore fluid compositions containing a base fluid; at least one synthetic fiber; and a particulate solid; where one or more of the at least one synthetic fiber and the particulate solid are completely or substantially acid soluble are provided. In another aspect, methods of reducing loss of wellbore fluid in a wellbore to a formation are provided, including: introducing into the wellbore a fluid composition comprising one or more synthetic fibers and one or more particulate solids.

Abstract: An acid soluble defluidizing pill for reducing fluid loss in a wellbore is provided that includes an oleaginous or non-oleaginous base fluid; at least one synthetic fiber; and at least one inorganic crystalline fiber; in which one or more of the synthetic fiber and the inorganic crystalline fiber are at least substantially acid soluble.

Abstract: A method for using a drilling fluid test device including a test cell including a perforated plate disposed proximate a first end of the test cell, a piston disposed within the cell, a first chamber formed between the perforated plate and the piston, the first chamber configured to receive lost circulation material (LCM), a second chamber formed between the piston and a second end of the test cell, the piston providing a seal between the first and second chambers, a fluid inlet disposed proximate the second end of the test cell configured to introduce fluid into a second chamber of the test cell, a filtrate outlet disposed proximate the first end of the test cell to discharge filtrate, and a pump in communication with the fluid inlet.

Abstract: Wellbore fluid compositions containing a base fluid; at least one synthetic fiber; and a particulate solid are provided. In another aspect, methods of reducing loss of wellbore fluid into and strengthening of a formation are provided, including: introducing into the wellbore a fluid composition comprising one or more synthetic fibers and one or more particulate solids.

Abstract: Wellbore fluid compositions containing a base fluid; at least one synthetic fiber; and a particulate solid; where one or more of the at least one synthetic fiber and the particulate solid are completely or substantially acid soluble are provided. In another aspect, methods of reducing loss of wellbore fluid in a wellbore to a formation are provided, including: introducing into the wellbore a fluid composition comprising one or more synthetic fibers and one or more particulate solids.

Abstract: An acid soluble defluidizing pill for reducing fluid loss in a wellbore is provided that includes an oleaginous or non-oleaginous base fluid; at least one synthetic fiber; and at least one inorganic crystalline fiber; in which one or more of the synthetic fiber and the inorganic crystalline fiber are at least substantially acid soluble.

Abstract: A method for using a drilling fluid test device including a test cell including a perforated plate disposed proximate a first end of the test cell, a piston disposed within the cell, a first chamber formed between the perforated plate and the piston, the first chamber configured to receive lost circulation material (LCM), a second chamber formed between the piston and a second end of the test cell, the piston providing a seal between the first and second chambers, a fluid inlet disposed proximate the second end of the test cell configured to introduce fluid into a second chamber of the test cell, a filtrate outlet disposed proximate the first end of the test cell to discharge filtrate, and a pump in communication with the fluid inlet.