When encountering losses, the priority is to determine the type of mud losses which will help you choose the suitable size and material for bridging or plugging material for the loss zone. Below is how to differentiate between them: Bridging Material Mechanism In Formation Structure Losses If losses are into the formation structure then our …
Electric wireline service companies run instruments on conductor lines inside the stuck drill pipe or tubing and are able to accurately determine the stuck point (check also stuck point calculations) of the pipe. The instruments called free point indicator tools are highly sensitive electronic devices that measure both stretch and torque movement in a drill …
When a pipe becomes stuck in the wellbore for any reason, one of the first steps is to calculate to determine at what depth or point the pipe stuck has occurred. This process is called stuck pipe free point calculation. When retrieving production tubing from a well, it is often expected to find that the …
Dogleg severity is a measure of the amount of change in the inclination, and/or azimuth of a borehole usually expressed in degrees per 100 feet of course length. In the metric system, it is usually expressed in degrees per 30 meters or degrees per 10 meters of course length. All directional drilling wells have changes …
Drill pipe or Drill collars can be unscrewed downhole by exploding a charge known as a string-shot (prima-cord folded up inside a piece of tubular plastic) inside a selected tool joint connection, just above the stuck pipe point ( check also free point calculation for stuck pipe), this operation can be described as mechanical drilling …
Wellbore strengthening can be achieved by utilizing stress cage pill theory through drilling mud types in the wellbore using bridging particles (marble and graphite) and an ultra-low fluid loss mud system. This theory is considered as a solution for the Lost Circulation Problem. Wellbore strengthening is designed to strengthen the wellbore so that depleted reservoirs …
A cross-link is a chemical bond that joins two separate polymer chains together. When this happens, the free movement of individual polymer chains is restricted. The fluidity of the polymer chains reduces as the degree (density) of cross-linking increases, and this will affect the physical properties of the drilling fluid. In the drilling oilfield, cross-linking …
The use of a gunk plug or squeeze may be considered if conventional LCM pills are unsuccessful in reducing or curing formation losses. The traditional gunk plug or squeeze involved dispersing Bentonite in diesel oil and spotting the resulting gunk plug across the thief zone. The gunk squeeze involves closing the annular BOP and squeezing …
Lost circulation In Drilling is any loss of whole mud to subsurface formations during any phase in drilling operations. Lost circulation is one of the primary contributors to high mud costs. In this article, we will handle their effects, types, types of thief zones, first actions & methods for locating loss zones. Also, we will …
Formation losses usually account for most of the additional costs when actual drilling fluid costs exceed estimated figures, which is why so much effort goes into preventing down-hole losses in the first place. If offset data is available, we can design the well to isolate lost-circulation zones behind casing pipe before drilling deeper formations requiring …