In general, to cure lost circulation, you have to follow two major steps: First, Make an assessment of the severity of a loss zone. ( see table-1) Second, Match the remedial material and the below techniques to it in terms of both the size of the material and its function. Prevention of mud loss is …
Lost circulation is the loss of borehole mud to the exposed formations in the well and is one of the most common problems of oil well drilling. Mud flowing into the formation implies that there is less mud return at the flow line than is being pumped or that there is no return at all. …
In general, there are two main causes of lost circulation in drilling operations problems which are as follows: As this article is one of five articles to cover the loss of circulation problems, I recommend visiting these links for a better understanding: Causes of lost of circulation In Drilling A) Invasion In many cases, lost …
About 60% of oil well footage is drilled in clays and shales. These rocks are neither hard nor abrasive and, thus, should be easy to drill. Problems arise, however, because of the soft and sticky nature of the cuttings produced. These cuttings absorb water from the drilling fluid, swell, and stick to the Drilling Bit. Balling …
Reaming & Backreaming Guidelines Reaming is a high risk operation that accounts for a large proportion of stuck pipe incidents. If reaming operations are conducted too fast, solids from wash-outs and cavings are introduced into the circulating system faster than the hole is being cleaned. This results in a drilling pack off. Do not assume …
Mechanical Pipe sticking is when any part from the Drill String such as Drill Pipe, Heavy Weight Drill Pipe HWDP, Drill Collars, Drilling Bit, or Bottom Hole Assembly BHA is stuck in a borehole due to mechanical reasons such as cutting accumulation, junk, extensive cement cutting and changing drill String geometry and cannot be recovered from …
Ledge in Drilling: The wellbore passes through the rock of varying types and ledges develop at the interfaces between layers of differing hardness. Closely spaced ledges decrease the effective diameter of the hole and produce a “shouldered” hole surface. Any type of casing string requires a smooth, more in-gauge hole diameter for free passage and …
Stuck Pipe In Cement Blocks Cuttings The Drill String becomes jammed in the hole by cement blocks cuttings falling around the Drill String. This mechanism occurs typically when : Hard cement becomes unstable around the casing shoe, open-hole squeeze plugs, and Sidetrack plugs. Preventative Action Rig Site Indications For Stuck-In Cement Cuttings Freeing Cement Blocks …
Collapsed Casing / Tubing Stuck Pipe Casing collapses either if pressure conditions exceed its original rated collapse pressure or the original collapse pressure rating of the casing is no longer valid due to casing wear and/or corrosion. Casing wear due to friction or corrosion decreases the effective collapse pressure rating of the casing, through decreased …
We mean by drilling junk any material, any tool or any piece of equipment may fall down from surface of from downhole Bottom Hole Assembly BHA and equipment. The junk may jams the Drill String and produce easily a good stuck. This type of stuck pipe usually occurs: Preventative Action For Wellbore Junk In Drilling …