Petrocafe-PDPUCAFE

BMC – control stratergy

2011-02-05T23:17:00.001-08:00

The point which lie on the pareto optimal curve are the points which are most optimal.

CLTF(closed loop transfer function):- Gc*Gp/(1+Gc*Gp*H)

OLTF(open loop transfer function):- Gc*Gp*H

The roots of the eqn in the numerator of a transfer function are called the zeros.

The roots of the eqn in the denominator of a transfer function are called the poles.

Total no of poles in a system is known as the order of the system.

Total no of poles lying at the origin determines the type of system. For eg:- if 2 poles value turns out to be zero, then its called a type-2 system.

Poles on the left side of the complex line can only be removed while on the right cant be because it makes the system unstable.

If any zero lies on the right side of the S-plane it is called non-minimum phase system.

If any pole lies on the right side of the S-plane then it is called unstable system.

Stability:- bounded i/p –> bounded o/p –> stable

Bounded i/p –> unbounded o/p –> not stable

unbounded i/p –> SP –> cant say ( cant comment on stability)

Transport phenomena types of fluids newtonian and non newtonian

2011-02-05T23:16:00.001-08:00

Types of fluids:-

Newtonian

Non- newtonian

Newtonian fluids:- the fluids that follow the newtons criteria are called newtonian fluids. Shear force= Ux/y where Ux is velocity in x direction. And y is the distance from the layer of minimum velocity.

The variation in velocity is only for certain thinkness after which the velocity is constant ,It is called boundary layer thickness.

boundary layer exists for every fluid. the part of liquid where resistance to flow exists is called boundary layer.

Fluids do not sustain shear stress , they are deformed under the action of external force and eventually flows.

In general when we plot a hydraulic gradient to velocity graph for newtonian fluids we get 3 regions , first for laminar flow, then for transient flow and the last one for the turbulant flow.

The region of transient flow is never the same for every time the experiment is repeated.

Eddies current:- for laminar flow such internal currents are generated.

Non- newtonian fluids:- that dont follow the newtonian criteria

properties:- apparent velocity depends upon the rate of shear and the previous shear history.

properties of both liquid and solid.

elasticity

heat and mass transfer coefficient are considerably affected by the behavior of the fluid.

2 types of non-newtonian fluids :-shear dependent , time dependent

For some fluids

Shear increases –> μa decreses –>shear thinning

shear increases –> μa increses –> shear thickening

Bingham plastic:- these need a minimum stress level to flow till that is achieved they behave like solids after that they behave like liquids.

Ry= μ( dUx/dy)^1-n this is power model

n=0 newtonian

n>1 shear thickening

n<1 shear thinning

newtonian fluids

Petroleum geology Fate of organic matter

2011-02-05T23:11:00.001-08:00

For the conversion of organic matter to petroleum you need atleast 2 things :- evolution of organic matter i.e abundance of organic matter and preservation( need a platform area for deposition)

Platform:- water depth ≤ 200 m . this is generally the region where fine grain particles are deposited and they can preserver the organic matter at its best.

Preservation in coarse grains is not possible as water can move through its pore spaces and so does the oxygen which oxidizes the organic matter thus ceasing the chances of preservation.

vuggy porosity [ note: if there is a mistake here, plz post comment to get it corrected] :- vuggy porosity arises due to dissolution of carbonates like limestone.

Petroleum geology shales ,kerogens, bitumin overview

2011-02-05T23:10:00.000-08:00

Oil shale:- shales containing oil are called oil shales. Oil was extracted from these shales by pyrolysis. pyrolysis is basically heating in absence of oxygen at 550° C .

Bitumin:- It is soluble in organic solvents , it is very well structured. Its of 3 types:-

a) labine -> very easily liberates hydrocarbon

b) inert -> high temp required for getting hydrocarbons

c) refractant -> can be used as an indicator of maturity in hydrocarbon source rocks, is a key method for identifying the temperature history of sediments in sedimentary basins.
(wiki pedia)

kerogens:- not structured and are insoluble in organic solvents, these the ones that have a good petroleum formation potential.

kerogen type-1 H:C ratio > 1.5

Vitrinite reflectance :- can be used as an indicator of maturity in hydrocarbon source rocks, is a key method for identifying the temperature history of sediments in sedimentary basins.
(wiki pedia)

Catagenetic regime -> it comes after diagenisis stage and before metagenisis. So VRo –> 0.5 – 2 %

Oil window -> VRo –> 0.7 – 1.3 %

Wish to know more,go here:- petrocafe.us.to

Petroleum geology - Kerogens

2011-02-05T23:06:00.000-08:00

Key learning of last two lectures:-

In a lagoon or silled condition we get more of sulphur while in an open water body (the water mass that is connected to the sea/ocean) we find less of sulphur in the sediments, this is because of presence of bacterias

In an open condition where there is agitation of air with water due to sea waves which dissolves the oxygen in water the bacteria Thiobacillus is found. This bacteria is responsible for converting sulphur in SO4. Thus decreases the content of sulphur in the sediments. The bacteria named desulfovibrio is responsible for the conversion of SO4 into S. In a Lagoon the oxygen content is depleted, so thiobacillus cannot survive as it is an aerobic bacteria and thus only desulfovibrio is present which converts the SO4 into S thus increasing the content of sulphur into the sediments.

Diagenesis:- Temp and pressure conditions for its initiation are:- 50 degree Celsius and pressure is 500-600 bar. It is the process which is responsible for converting organic matter into kerogens.

Pristane – phytane :-

The presence of pristane and phytane in a crude is a supportive point for the organic theory of origin.

The chlorophyll when undergoes a oxydizing environment it finally yields the pristane and if goes through an reducing one the yields phytane. Thus depending upon the ratio of pristane to phytane we can make out what kind of environment was present during that period. These two are known as geochemical fossils.

The content of particulate organic matter is much less than dissolves organic matter in the ocean.

The process of formation of kerogen:-

Protein and polysaccharides(highly organic bipolymers) à enzymatic microbiological degradationà Amino acids and sugar (mononers) à random polymerisation and condensation à Fumic acid, humic acid, humin ( geo polymers) à increasing condensation and insolubalisation à Kerogens

Lipids(highly structured) à preservation with minor alteration yields kerogens

Organic matter obtained from algae is always saprophylic , which is rich in hydrogen and has less of NSO( nitrogen, sulphur and oxygen)

Type of kerogens:-

Type- 1 , type-2 , type-3

TYPE- 1 :-

Has high H:C ratio 1.5 or more

Has low O:C ratio less than 0.1 , small amount of oxygen that too in ester 4.6%

Much lipid material , particularly aliphatic.

Produces large yield of volatile and extractable compounds , upto 80% by wt prolific oil shales.

Sources:- selective ammulation of algae and severe degradation of OM. Abundance:- low

TYPE-2 :-

High H:C ratio

Low O:C ratio

Abundance ofModerate length chains of aliphatics and naphthenic rings

Rather abundant amount of ester group oxygen = 10.3 %

Can provide commercial oil shales but less than that of type-1

Source: Marine sediments of phytoplanktons , zooplanktons, bacteria deposited in reducing environment

Abundance:- abundant

TYPE-3 :-

Low H:C ratio less then 0.1

High O:C ratio 0.2 to 0.3

No ester group, oxygen content is still in other forms = 27.5 %

Less efficient for oil but a good gas source

Source:- continental plants

Abundance:- high

Get to know more at :- petrocafe.us.to

Transport phenomena manometers

2011-01-27T07:01:00.000-08:00

Key learning in transport phenomena :-
Unit of viscosity in oil field units is:- centipoise
Dimensional equation:- The eqn having a constant which has units is called a dimensional eqn.
1 ft = 30.48 cm
1 ft^3 = 0.0283 m^3
Compressible fluids:- If density changes with pressure and temp. then the fluid is called compressible fluid.
Fluid is a substance that doesnt permanently resist distortion.
Static pressure of fluid flow is measured in the direction parallel to the flow of the fluid.
dynamic pressure is measured in the perpendicular direction to the fluid flow.
Static pressure has to be measured about 50 diameters away from any bends, to get the accurate values.

Petroleum geology Duplex theory of origin

2011-01-26T09:09:00.000-08:00

Duplex theory of origin of petroleum
This theory says that initially the hydrocarbon may be formed abiologically due Fischer - tropsch reaction. Then it must be acted upon by the living organisms like bacteria thus giving rise to the organic hydrocarbon.
The Fischer tropsch reaction is in general the reaction of carbon monoxide with hydrogen giving rise to the hydrocarbon and water.
It can be given as follow:- C+ Fe+H+OH------>CH4+C2H6+C3H8+C4H10+FeO
CO2+HOH+Fe---->CH4+FeO
C+HOH+Fe-->CH4+CO2+H2
Temp needed is 500°C
Robinson in 1963 and Szatmari in 1986 explained the same theory in different forms. Szatmari used plate tectonics to explain it.

Petroleum geology organic origin theory

2011-01-26T08:38:00.000-08:00

Supports for organic origin theory:-
Vast amount of organic matter is found in sedimentary rocks. Hydrogen and carbon are predominant in remains of plants and animals.
Most of the crudes have porphyrin in them that is the most essential element of life form.

If M in porphyrin is replaced by Fe then we get hemoglobin.
If M is replaced by Mg then we get Chlorophyll
If M is replaced with Ni or V we get a cyclic porphyrin .
Porphyrin is not stable above 200 ° C . So inorganic theory is proved faulty, as the mantel is about 33 km below the surface and average temp gradient is about 25° C/km . So the temp till we reach mantel would be about 800 ° C where porphyrin cant exist, so it shouldnt be present in the crude if it was formed inorganically.
Most of the crudes contain Nitrogen which is the basics element of amino acids that form the basis of life form.
All crudes possess the property of rotating the plane of polarised light. such a property is possessed by cholesterol which is essential component of animals and plants. The inorganic substances that possess this property are cinnaber(HgS) and quartz(SiO2)

Drilling and well completion

2011-01-26T03:36:00.001-08:00

key learning DWC :- [note: special thanks to Vikas for providing us these notes of DWC]

Different system in rig:

-power system

-hoisting system

-circulating system

-rotary system

Various part of rig:

Power system-mechanical drive

-DC generator(diesel power internal combustion engine or it is internal combustion engine used to provide electricity–Prime mover )

-AC generator

Used:-

-for draw works

-mud pumps

-rotary table

-Mechanical drive-wheel,chains

-most widely used –AC-SCR system

SCR-silicon controlled rectifier

-formula for Horse power=load/efficiency

Where efficiency <1.

Efficiency factor(E)=energy(output-input)/energy output

Where E=(0-1);

-output is from prime mover’s.

-losses in form of friction

basics of measurement and control key points

2011-01-26T02:30:00.000-08:00

Some key points about open loop system:

1) Very simple and easy to understand.

2) No safety guarantee.

3) No accuracy guarantee.

Some key points about closed loop system:

1) Closed loop systems are always automatic system.

2) Most of the closed loop system is divided in two parts,first is Measurement which measure and analyses the data of system and other is Controller which control the system it may be automatic or self control.

some of the important terms:

 Multi-input system: More than one input

 Multi-output system: More than one output

 In a plant there’s a control system consisting of control component which give the response.

i/p(Excitation) -> Control component -> o/p (response/behavior)

 Unit step i/p: in which the value of input is 1.

Key points about Transfer function:

 It gives the characteristics of the system.

 Time varying behavior can be known using laplace transformation.

 Frequency response behavior can be known using fourier system.

 EXAMPLE

U(t) (excitation) -> Control component -> y(t) (response)

For this the transfer function is

= α y(t) / α u(t) at t=0 and y(t)=0(initial condition) (alpha=laplace of that function)

= y(s) / u(s)

 Transfer function only defined for a linear system.

 Linear system can be defined or measured by superposition theorem, Homogeni

basics of measurement and control superposition

2011-01-26T02:29:00.000-08:00

The systems need to be controled because there are disturbances that are created which deviate the system from its set point or say set parameters.

Kind of disturbances:-

1) stoichistic

2) deterministic

Control systems:- The system consisting of various componenets that are connected logically is a control system.

optimality:- Minimum input + [error--->0] = optimality (optimal control)

Transfer function:- relation between input and output.

TF :- laplace(output)/laplace(input) |initial condition zero

Superposition:-

U1 + U2 —-> control system —-> Y

for U1=0 –> Y=Y1

for U2=0 –> Y=Y2

then for a linear system Y=Y1+Y2, this is superposition theorem.

Homogenity:- if input is 0 then output is zero is the priciple of homogenity.

then a simple example based on laplace transformation was solved in the class, to find the TF(transfer function)

basics of measurement and control systems

2011-01-26T02:02:00.000-08:00

Nothing special was taught, only an overview of Measurement and Control was given. The two things that were explained were :-

1)open loop system:- in such kind of system there is no importance of the output quality , so there is no feedback mechanism to measure the variables and control them.

INPUT——–>OUTPUT(no quality requirement)

2)closed loop system:- in such a system the importance of output quality is high and hence there is a feedback mechanism made to control the system variables to maintain the system at the set point conditions. So there are sensors to measure the variables and controllers to control or say keep the system at required state :D

INPUT——control—->output( required quality) |________feedback____|

that was the entire classs 1 of BMC

As per suggestion of kunal , the below section is added:-

Summing point is a point that gathers the information(process variable/value) given by sensors and the set parameters to find an error in the process output, so that an feedback can be generated to control the process and obtain an output as per set parameters.

Error= Set parameter(SP) – Process variable/value (VP)

Transport phenomena dimensional analysis

2011-01-26T01:58:00.000-08:00

transport phenomena

DIMENSION ANALYSIS

For the introduction he only told about the uses of DIMENSION ANALYSIS which all of us knows and if ne1 wants it then please let me knw(SAURABH)….

k one thing which he mentioned was about DIMENSIONLESS GROUPS…..

DIMENSIONLESS GROUPS = Group of symbols may be put together , either by theory or based on experiment, that have no net units , these are called dimensionless groups.

No. of dimensionless groups = (No. of variables) – (No. of fundamental dimensions)

eg: REYNOLD’S NUMBER

STANDARD AND OTHER SYSTEM OF UNITS

———–> WHAT IS “SLUG“????

SLUG is a unit of MASS in the BRITISH ENGINEERING SYSTEM!!!!

BRITISH ENGINEERING SYSTEM:

In this system MASS is not a FUMDAMENTAL DIMENSION whereas FORCE is a FUNDAMENTAL DIMENSION…..

MASS is derived!!!!

Dimensions used in this system:

L F T

ft lb_f s (ft=feet lbf=pound force s=seconds)

1 slug = 1 lb_f / (1 ft/s²)

—-> FOR 1 lb of mass, 1 lb_f force produces 32.1740 ft/s²acceleration

FTS :

In this system FORCE is not a FUMDAMENTAL DIMENSION whereas MASS is a FUNDAMENTAL DIMENSION…..

FORCE is derived!!!!

Dimensions used in this system:

L M T

ft lb s (ft=feet lb=pound s=seconds)

—-> FOR 1 lb of mass, 1 POUNDAL produces 1 ft/s²acceleration

where POUNDAL is the force….

F (Pound Force) = ( MASS (Pound) x ACCELERATION (ft/s²) ) / g_c

Pound weight force = Pound force ………..(where g = 32.1740 ft/s²)

Normally in various books problems are solved by using both ‘g_c’ and ‘g’….

Where, g = g_c/32.1740

if you have ne correction to be made in this then please let me know(SAURABH SURYAWANSHI)

Added section:-

Generally to increase the no of dimensions and to differentiate between various entities of same units, L is taken as a vector and is expressed in terms of (Lx ,Ly,Lz)

work:- M Lx T^-2 Lx

Torque:- M Lx T^-2 Ly

angular velocity:- (Lx/Ly) T^-1

frequency:- T^-1

Shear stress:- F/ Lx Ly^1/2 Lz^1/2

Scaling of degree R, degree F, degree C and Kelvin(K) :-

100 delta(degree C) = 180 delta(degree F)

same is for K and degree R

The relation between R and K :- [note: scaling and relation are different terms dont mix them up]

R = 1.8 K

Petroleum geology- theories of origin

2011-01-26T01:41:00.001-08:00

Petroleum geology

Theories of origin of petroleum:-

organic origin theory is widely accepted, as 97% of petroleum reservoirs are found in sedimentary rocks. Rest 3% are found in metamorphic as well as igneous rocks, that too with some conditions.

Inorganic theories:-

1) cosmic theory:- Bertheiot(1865) ,mendaleef(1877) suggested the formation of petroleum in earths interior by action of water on metallic carbides such as those of Ca and Fe.Another proposed mechanism involved in the interaction of alkali metals with co2 and water.

Metallic carbide + H2O vapour = CH4 + metallic hydroxide

Alkali metals + Co2 + H2O vapour = CH4 + alkali hydroxide

2) mantle theory/Gold’s earthquake out gassing theory:-

Enriched Delta(13C) of methane from hotspots of red sea, lake kivu(east africa) and pacific rise depicts an abiogenice origin(Mac donald).

Delta(13C) content in crude oil is -30%o(i.e per millenium)

some other key learning:-

oldest rock is found in greenland which is 4.2 billion years old.

2nd oldest rock is found in chota nagpur(singhbhum)

Origin of most petroleum in the world dates back to mesozoic to paleozoic

The origin of petroleum found in india lies in the cenozoic age.

NELP:- new exploration licensing policy [ it is now about 15 years old ]

Please post your comments for corrections and suggestions

petroleum geology

2011-01-26T01:25:00.001-08:00

[ there might be some errors in the text below]

porosity is of 2 types:-
bulk: The porosity calculated considering the total pore spaces.
effective: the porosity calculated considering the pores that can hold hydrocarbon.

The component that will occupy the pore depends upon the pore size

Sedimentary texture:-structure formed due to sedimentation. It is of two types:-
1)that forms on surface:- Depends on flow and deposional enviornment(also known as bed forms)[example:ripple marks]

2)that forms in beds:-current bedding. enourmous importance in studying the depositional history.

Sedimentary structures are used to know the paleocurrent flow.

most indian oils are generated from type-3 kerogens. type-3 kerogens are derived from terrestial organic matter.

Transgression—> flooding –effect–>ground water table also rises —>controls eroison–>sedimentation is less

Regression:- base level of eroison decreases, area available for deposition decreases.

During the last glacial period the sea level decreases about 138 metres. lot of shelf was exposed, the base level of erosion went down
so no deposition in vast area Because slope of shelf is very less. Such an kind of unconformity formed is known
as 1st order unconformity.

Primary migration:- low permiability rock, Fine grain rock.

secondary migration:- high permeability rock, coarse grain rock.

For any suggestions and questions please post comments.

Petroleum geology

2011-01-26T01:23:00.000-08:00

Some key learning points:-

bubble point can be defined on basis of Temp and also pressure(which is the conventional way) individually . Also it can be defined on basis of both Temp and Pressure simultaneously.

what is a petroleum system??

ans: the system consisting of a source rock, a migration mechanism( primary or secondary) , a reservoir rock and a cap rock is known as a petroleum system. There are in all 70 petroleum systems in india, out of which around 35 are identified to have a potential.

Around 3.14 million sq.Km is covered with sedimentary rocks in india.

In a petroleum system there are potential areas where petroleum is found which are called oil pools, ONGC calls oil pools as assets.

Hello

2011-01-26T01:07:00.000-08:00

Hello guys this is going to be a blog for getting lecture notes of Petroleum. The notes that would be added here would be from PDPU( pandit deendayal petroleum university).
Hope you enjoy the blog keep checking the blog to get notes daily. :D

We also have a running website for petro discussion , at Petrocafe.us.to . You can even check it out there.