The Cement evaluation tool (CET) uses ultrasonic acoustic pulses from a rotating transducer and measures radially instead of axially. The transmitter emits ultrasonic pulses between 200 and 700 kHz and measures the received ultrasonic waveforms reflected from the internal and external casing interfaces. The rate of decay of the waveforms received indicates the quality of …
Prior to cementing in drilling oil & gas job, laboratory testing must be carried out to ensure that the correct recipe is used considering all of the existing conditions and cementing additive properties (oil well cement properties) according to API Recommended Practise. Testing must be conducted on the actual on-site material to be used. The …
Coiled Tubing Drilling (CTD) has evolved rapidly since its first operations in 1992. The main motivation for drilling with coiled tubing was the presence of large diameter CT which makes it easy to deliver the required hydraulic horsepower to the downhole. This horsepower is mandatory for hole cleaning, transferring cuttings in the annulus, and providing …
This article covers all formulas that are used while well control situations on the drilling rig ( Check also: Drilling rigs Types). Pressures Formulas HYDROSTATIC PRESSURE (all depths TVD): Constants: PRESSURE, psi = Mud Weight x Constant x Depth, (TVD) PRESSURE GRADIENT, psi/ft = Mud Weight x Constant OR = Pressure, psi ÷TVD, ft MUD …
Well cementing plays a very important role in the construction, completion, and abandonment of wells since the cement performs vital functions in supporting the casing and drilling wellhead equipment. The casing cannot perform the functions it is designed for, described elsewhere unless effectively cemented in place. The cement forms an impermeable barrier to the passage …
The complete removal of the mud from the annulus (Mud Conditioning Simple Guide For Better Cementing) and its replacement with a good cement slurry is the major requirement for a good cement job. Cement placement is influenced by: Good cement placement can only be achieved when all parameters are optimally fulfilled. Single Stage Cement Jobs …
The cement evaluation is necessary for determining the zonal isolation and the top of cement. The position of the top of cement can be established in three ways: Comparison of the actual TOC with the intended TOC may give an indication that losses (Check also Mud Losses) (unexpectedly low TOC) or channeling (unexpectedly high TOC) …
Casing Tallies Versus Liner Tallies There are two different types of tubular tallies: 1) a casing tally spreadsheet and 2) a casing liner tally. A casing tally works from a fixed point at the wellhead (e.g. hanger landing point) and the formulae in the spreadsheet calculate the shoe depth by adding the length of each …
Pipe Washout in oil and gas is a sudden problem that may happen during any stage of drilling the well and may cause a parting of the string and the following fishing in drilling operations that will increase well time and cost. Drill Pipe Washouts Causes & Precautions As with all downhole problems, prevention is …
Casing repair is not exactly a drilling fishing job, but if the casing collapses, splits, or parts you’re fishing skills can help you repair the casing. Casing repair involves using a variety of tools downhole. Each casing failure must be evaluated based on the specific conditions of the failure before a method of repair can …