These logs are capable of detecting formations less than 1.0in. thick, if the mud cake is very thin. Micro-laterologs can be used in salt muds and high resistivities. Their response will be affected by mud cake greater than 3/8" thick. Typically used to measure Rxo and determine permeable beds by detecting mudcake. Limitations Shallow invasion … Continue reading Micro-Resistivity
Short Spaced Resistivity
Short Normal The usefulness of the curve will be determined by the vertical resolution. The short normal (SN) is useful as long as the contrasts between the drilling fluid and formation resistivities are not too great. Resistivity beds will appear thinner by the arm spacing (16ins.), and conductive beds appear thicker by the same amount. … Continue reading Short Spaced Resistivity
Gamma Ray
Measures the natural resistivity of the formations in the borehole. Good for the identifying lithology and correlation purposes. The GR log usually reflects the shale content of the formations because of the concentrations of radioactive materials in the shales/clay. Shale free sandstones and carbonates have low gamma ray values unless contaminants are present. They are … Continue reading Gamma Ray
Spontaneous Potential (SP)
Spontaneous Potential (SP) This is a record of the direct current voltage differences between the naturally occurring potential maintained by a movable electrode in the borehole and a fixed potential located at the surface. The potential is as a result in the difference between the salinity of the drilling and formation fluid. The SP log … Continue reading Spontaneous Potential (SP)
Porosity Logs
Sonic Log Essentially it emits a sound pulse and has a receiver that picks up the sound pulse as it passes the receiver. This produces a transit time and generates a wave form that can be interpreted. In the sonic log the velocity of the wave form through the rock matrix will help to determine … Continue reading Porosity Logs
Intro To Logging
Introduction The logging of a well bore is the process of measuring the electrical resistivity of the surrounding formation and the fluids within. It is known that the electrical resistivity of rock is high however the resistivity of minerals and fluids that occupy the pore spaces of said rock have proven to be low in … Continue reading Intro To Logging
Reservoir Evaluation (Intro)
This section will be a brief introduction into the methods used to evaluate the well bore environment, the formations drilled and the formations beyond the wellbore. Typically this is done to better the operators’ knowledge base and understanding of the formations it encounters, build a better model of the drilling environment which in turn helps … Continue reading Reservoir Evaluation (Intro)
Sedimentary Environments
Facies A body of rock with specific characteristics. Defined on the basis of colour, bedding, composition, texture, fossils and sedimentary structures. Facies Sequences A sequence of facies as the pass from one to another. The sequence can have an abrupt or erosive boundary or a hiatus. In this case there is a coarsening upward sequence … Continue reading Sedimentary Environments
Geological Time
The Principle of Uniformity This states that the processes operating today affecting the earth have been operating unchanged at the same rates throughout the earth’s history. Relative Time The occurrence of a geological event relative to each other. This helps in the dating of geological occurrences. It helps with the identification of a geological continuum. … Continue reading Geological Time
The Oil and Gas Story
Introduction There are three types of rock types that are studied when considering the geological environment. They are no particular order: Sedimentary Igneous Metamorphic The circumstantial evidence has suggested that hydrocarbons that are formed and deposited are strongly associated with sedimentary rocks. They are the result of altered organic material derived from microscopic plant and … Continue reading The Oil and Gas Story
Compressors-Intermittant Compression
The best known example of these are reciprocating piston compressors, the major component being the piston that moves within a cylinder. It operates like any other reciprocating cylinder system, on one cycle te pressure within the cylinder drops and the fluid enters. As the piston proceeds the fluid is compressed and then dis-charged. They may … Continue reading Compressors-Intermittant Compression
Compressors-Continuous Compression
In a sense they function like pumps, they perfom mechanical work on a process fluid. This results in the reduction of fluid volume, but an increase in the fliud pressure. The compressors transfer this energy either continuously or intermittently. Continuous energy transfer compressors, are either ejector or dynamic. The dynamic compressors are either axial or … Continue reading Compressors-Continuous Compression
Pumps-Dynamic
Dynamic pumps unlike positive displacement pumps output fluid over a range of flow values for a given range of rotational values. Centrifugal pumps are dynamic and are very common in industrial applications. They are typically made up of one main rotating component, an impeller, and several stationary components. The outer housing is the volute aka … Continue reading Pumps-Dynamic
Pumps
The pump is a mechanical device that moves liquid from one point to another, by increasing the pressure differential between two points. The pump as a device usually functions by converting energy and by using mechanical parts to initiate this pressure differential. They are driven by any number of equipment, from electric or hydraulic motors … Continue reading Pumps
Maintenance
Maintenance is the process of ensuring a certain standard is upheld by constantly looking into problems and fixing them, or trying to anticipate and pre-empt. Usually maintenance is preventative, that is, it executes tasks on equipment so as to prevent equipment problems and or failure. Preventative maintenance is known as scheduled maintenance, and as its … Continue reading Maintenance
Valve Problems-Leaking
This is self-explanitory, the valve has a leak, due to some fault of the valve or operation out side of the valve's parameters it allows for the release of process fluids. Leaks usually eminate from either the base of the stem as it enters the valve body, or it ma leak internally at the valve … Continue reading Valve Problems-Leaking
Valve Problems-Cavitation
Like all equipment valves are subject to problems in operation, quick and accurate identification and troubleshooting of the problem is necessary to ensure that the problem doesn't impede the process or result in equipment failure. The valve body is prone to cavitation, this occurs when the fluid within occupies 2 phases, vapour and liquid, essentially … Continue reading Valve Problems-Cavitation
Valve Actuators
These are used to remotely control a valve and are common in the modern industrial plant environment, they represent the final element of control for a particular process. They may be either air, gas or hydraulic and are classified depending on the power supply used to actuate the valve. Pneumatic actuators use air to control … Continue reading Valve Actuators
Valves
The gate keepers of any industrial process fluid flow, these devices are responsible for or aid in the control of fluid flow. They are mechanical devices that can be interacted with directly or indirectly. Directly the operator can physically/manually operate the valve to open, close or throttle the fluid flow passing within. Indirectly the valve … Continue reading Valves
BOP Testing, Inspection and Maintenance
(a) BOP pressure testing timeframes.You must pressure test your BOP system: When installed; and Before 14 days have elapsed since your last BOP pressure test. You must begin to test your BOP system before 12 a.m. (midnight) on the 14th day following the conclusion of the previous test. (b) BOP test pressures.When you test the … Continue reading BOP Testing, Inspection and Maintenance