The causes of tight holes include: Insufficient inhibition, Mud weight, Lubricity and Hole cleaning. All these factors are important and comparisons should be made between wells with and without problems, to identify the critical factors. Tight hole is mainly encountered when coming out of the hole. It occurs where sometimes a fresh hole has been … Tripping Procedure in tight hole
The first actions taken when the drillstring becomes stuck have a great influence on the chance of success. The information detailed belowl give guidance to the correct early response when the pipe becomes stuck. Effective Pull On Stuck Pipe When determining the pull on differentially or mechanically stuck drillpipe, the actual weight of the string … Effective Pull On Stuck Pipe
The following table lists those problems commonly encountered in drilling extended reach (ERD) and horizontal wells and recommendd precautions. Inefficient Hole Cleaning & Reduced Borehole Stability Maintain high annular velocity, use turbulent flow pattern wherever possible Use low rheology fluid (horizontal sections) Use extended rheology muds for high angle 12.1/4in and larger hole sections Pump … Problems encountered in drilling extended reach and horizontal wells
In the event the casing string becomes stuck and all attempts to get it free are unsuccessful then , remedial action options shall differ according to the type of wellhead that is being employed and the depth of stuck point in relation with the different formation. The option to set the casing high can only … Stuck Casing – Remedial Action
Responsibilities of the Company Drilling Supervisor, Specialist Contractor Engineer, Drilling Contractor Toolpusher, during fishing operations. Company Drilling Supervisor: The overall responsibility and supervision of all non-standard operations rests with the Company Drilling Supervisor. He shall also ensure that fishing equipment is available on site for all non-standard equipment run in the hole. Drilling Contractor Toolpusher: … Responsibilities during Fishing Operations
This article describes force multiplying fishing tools: Jars, Accelerators, Bumper Subs. Drilling/ Fishing Jars If a fishing specialist contractor is used, the contractor should be consulted on a case by case basis for the optimum selection and placement of jars. Accelerators A gas-charged (N2) accelerator or “intensifier” may be run to greatly increase the effectiveness … Fishing Tools: Drilling/ Fishing Jars,Accelerators, Bumper Subs
When equipment has been lost or is stuck in the hole, the following points shall be considered in deciding the optimum course of action: The type of equipment in the hole to be fished (drillpipe, collars, junk bit cones etc). The condition of the hole/mud. Will formation instability cause the hole to deteriorate ? Is … Fishing Planning and Preparation
The table below presents the types of fishing tools and their applications Type of Fishing Job Type of Fishing Tool Names of Tools Recovery of Tubular Fish Connecting Tools -External Catch -Internal Catch -Accessories Washover Tools Force Multiplier Overshot Die collar Taper tap (poor class of tool: overshot … Fishing tools selection
This article describes the following fishing tools: Magnets, Lead Impression Blocks, Rope Spears, Taper Taps and Die Collars. Magnets The following guidelines should be used when using magnets: The force of some magnets decreases with the age of the magnet. For this reason, when the magnet is not in use, the cover plate on the … Miscellaneous Fishing Tools
Junk subs are constructed with rib guides which are welded to the main body. These guides assist in preventing the cup from becoming crushed and guide the tool. Junk subs are available in various lengths. Guidelines The following guidelines shall be used when running junk subs: The mud stream agitates the junk and causes it … Fishing with Junk Subs