Technical- Part 8

Question 1

Acidizing: Damage

Answer 1

Damage – emulsions, wettability, water block, bacteria, fines and clays, scales

Question 2

Acidizing-Sandstone ​

Answer 2

Sandstone – sedimentary rocks consist of silts and clays. HCL does not attack silicates (quarts, feldspar), but HF does. HCL is designed to work on clays. Some are unstable like Zeolites and Chlorites. HCL is pumped to clean out carbonates. HF is used to eat on silicates.

Question 3

Acidizing-Organic HF

Answer 3

Organic HF – less corrosive, reaction rate ¼ as of mudacid

Question 4

Acidizing: Clay acid -

Answer 4

Clay acid - retarded mud acid by hydrolysis process where HF is released at slow rate

Question 5

Organic clay acid –

Answer 5

for high silts and clays and high temps

Question 6

Acidizing-Carbonate

Answer 6

Carbonate – dissolution of rock, creating wormholes and not removing damage(sandstone acidizing) fluids like HCL, formic and acetic acids, DGA, SXE, SXEHT, SDA, and VDA.

Question 7

ClearFRAC

Answer 7

ClearFRAC – viscoelastic surfactant mixed with KCl. It is made of worm like missiles. Breaks down upon contact with hydrocarbons, 95% conductivity, longer xeff, low friction, not shear sensitive, simple to make.

Question 8

SXE

Answer 8

1. SXE – super X emulsion, 70:30 acid in oil. Oil external emulsion, control leakoff.

Question 9

SDA

Answer 9

SDA – self diverting acid. Polymer/crosslinker system. Viscosifies at pH of 2.. breaks at pH of 4-5. As acid spends, the acid will lose viscosity.

Question 10

VDA

Answer 10

VDA – viscoelastic diverting acid. VES system viscosifies at pH of 2, breaks upon contact with hydrocarbons.

Question 11

SAPPHIRE VF–

Answer 11

Viscoelastic surfactant- water base fluid,

Question 12

Well Testing

Answer 12

Well Testing – tool for reservoir evaluation and characterization

• investigates larger volume of the reservoir than logs
• provides estimate of effective perm under in-situ conditions
• provides est of NWB skin
• provides est of boundary distance

Question 13

Geology

Answer 13

Petroleum system requires: Source, Reservoir rock, cap rock (shale), trap (structural/stratographic)

Porosity: void space, determines amount of fluids that can accumulate

Permeability: connected pores, ability of fluid to flow in/out of the reservoir

Question 14

IPR Curve

Answer 14

• Darcy-radial flow
• Darcy with Vogel: corrects for Darcy @ Pw
• Jones Gas IPR- high permeability gas wells in turbulent flow NWB

Question 15

Nodal Analysis

Answer 15

Nodal gives quick visual of Stimulation impact to production (shows how much Skin is, what it decreased by)

Question 16

Single Phase vs Muli Phase Flow

Answer 16