Drilling fishing

The drill pipe itself can be used for formation evaluation (Drill Stem Testing— DST), well stimulation (fracturing, acidizing), and fishing operations. 

To avoid costly fishing operations, loss of material and time, the drill pipe must be carefully inspected according to the following procedure [30] ... 

Types of Jars. There are two general classes of Jars fishing Jars and drilling Jars. 

A fishing Jar is used to free stuck drill string, and is added to the drill string only when the string becomes stuck. 

There are a number of causes for fishing operations. Many of the causes are preventable by careful planning of the drilling operation and being very watchful for the indication of possible future trouble [149]. 

Ajar is a device for providing an impact load to the fish when the fish cannot be retrieved by normal string and derrick forces. There are purely mechanical jars and hydraulic Jars (see the section titled Drilling Bits and Downhole Tools for details on drilling Jars). In a fishing operation the Jar is usually placed... 

There are items other than tubulars that must be fished from boreholes. These are drill bit parts, pieces of downhole tools left in the borehole and hand tools accidentally dropped in the borehole. Nearly all of these items cannot be drilled by a normal rock bit. Such items are called junk. 

Milling Tool. The milling tool is a common device used for fishing junk. The milling tool is used to grind the junk into small pieces so that the pieces can be circulated to the surface or removed in a junk basket. Figure 4-364 shows the various milling tools that can be used to drill up junk in the bottom of the... 

Moore, E. E., Fishing and freeing stuck drill pipe, The Petroleum Engineer, April 1956. 

Base fluids (BFs) represent the major ingredient of nonaqueous drilling mud systems. They act as the continuous phase in OBMs and SBMs. Oil-based fluids (OBFs) such as diesel and mineral oils have been replaced with synthetic-based fluids (SBFs) because of the deleterious environmental hazards of OBMs. The SBFs contain fatty adds which are usually derived from vegetable oil (e.g., palm oil) or fish oil. SBFs usually constitute about 50-90% by volume of the fluid portion of the SBM [27] and about 20-40 % of the mass of the mud [35]. Ethers, esters, acetals, polymerized olefins (poly-a-olefins, linear a-oleftns, and internal olefins), enhanced mineral oils, and paraffins are used most frequently as SBFs (Table 11.2) in mud formulations [8, 36, 37]. 

To investigate further the chemical characteristics of potential alternative emulsifiers, the water-soluble fractions (WSFs) of each emulsifier were measured [61]. The samples were analyzed for total recovered hydrocarbons (TRH) in the C10-C36 region and PAHs [3, 62]. The chemical analysis of the emulsifier WSFs did not detect PAHs. Consequently, in the future, use of low-fluorescence emulsifiers in the reformulated Syndrill 80 20 (Mod) will allow the measurement of biliary fluorescence as a biomarker of exposure in field-caught fish attracted to cutting piles, with any detected fluorescence eliminating the drilling mud Syndrill 80 20 (Mod) as a source of fluorescent metabolites in the biliary secretions. 

Bakhtyar, S. Gagnon, M.M. Exposure of fish to individual ingredients of synthetic based drilling muds (SBMS). In press Journal of Environ. Monitor, and Assess. DOI 10.1007/sl0661-011-2342-x. (2011)... 

---