What is rock Eval analysis?
What is rock Eval analysis?
Rock Eval pyrolysis is used to identify the type and maturity of organic matter and to detect petroleum potential in sediments. This is the phase of volatilization of the very heavy hydrocarbons compounds (>C40) as well as the cracking of nonvolatile organic matter.
What is S2 in Rock Eval analysis?
Rock Eval pyrolysis S2 = the amount of hydrocarbons generated through thermal cracking of nonvolatile organic matter.
What does PI mean in oil and gas?
productivity index (PI) 1. n. [Well Completions] A mathematical means of expressing the ability of a reservoir to deliver fluids to the wellbore. The PI is usually stated as the volume delivered per psi of drawdown at the sandface (bbl/d/psi).
How do you identify kerogen?
Determining kerogen quality Type I kerogen is the highest quality; type III is the lowest. Type I has the highest hydrogen content; type III, the lowest. To determine the kerogen type present in a source rock, plot the hydrogen and oxygen indices on a modified Van Krevlen diagram (Figure 1).
What is vitrinite coal?
Vitrinite is a type of maceral, where “macerals” are organic components of coal analogous to the “minerals” of rocks. Vitrinite has a shiny appearance resembling glass (vitreous). It is derived from the cell-wall material or woody tissue of the plants from which coal was formed.
How do you calculate hydrogen index?
The number of hydrogen atoms per unit volume divided by the number of hydrogen atoms per unit volume of pure water at surface conditions. The hydrogen index (HI) is thus the density of hydrogen relative to that of water. It is a key factor in the response of a neutron porosity log.
What does PI mean in production?
Productivity Index
Productivity Index is the measure of the ability of a well to produce hydrocarbons at a commercial rate.
What is a high productivity index?
The productivity index is a measure of the well potential or ability to produce and is a commonly measured well property1. The symbol J is commonly used to express the productivity index; as well as, being the preferred symbol by the Society of Petroleum Engineers.
What is the types of kerogen?
Kerogen quality
| Kerogen type | Predominant hydrocarbon potential | Amount of hydrogen |
|---|---|---|
| I | Oil prone | Abundant |
| II | Oil and gas prone | Moderate |
| III | Gas prone | Small |
| IV | Neither (primarily composed of vitrinite) or inert material | None |
What makes a good source rock?
Source rocks are usually shales or limestones (sedimentary rocks). To be a productive source rock, the rock needs time to mature (time to form the oil and/or gas) and the hydrocarbons need to be able to migrate to a reservoir or seep. Marine rocks tend to form oil while terrestrial, or land, rocks tend to form gas.
How is coal rank measured?
The rank of a coal is determined primarily by the depth of burial and temperature to which the coal was subjected over time. With increasing temperature, peat is converted to lignite, a very soft, low-rank coal.
How is the pI of a rock calculated?
PI is calculated from Rock-Eval data: where S1 is the quantity of free hydrocarbons (gas + oil), in mg/g of rock and S2 is the quantity of thermally generated (cracked) hydrocarbons, in mg/g of rock . PI increases continuously through the oil window up to a value of 0.50. The following cutoffs can generally be applied.
What are the parameters of Rock Eval pyrolysis?
Rock Eval pyrolysis, which is traditionally used to identify the type and maturity of organic matter and to detect petroleum potential in sediments, i.e. source rocks, is now routinely determined on shale resource plays. The four basic parameters obtained by pyrolysis are: S1 = the amount of free hydrocarbons (gas and oil) in the sample.
What do you need to know about Rock Eval?
It involves two heating stages to obtain free and sorbed hydrocarbons (Sh0 and Sh1, corresponding to traditional S1), as well as a residual hydrocarbon potential measurement (Sh2, corresponding to S2): For both types of analysis, finely milled rock samples are required.
What is the purpose of TOC and Rock Eval?
The purpose of TOC and Rock-Eval pyrolysis is to screen for the presence of source rocks, and to determine their hydrocarbon generation potential, the type of organic matter present and an indication of its thermal maturity (Espitalié et al. 1977). The presence of migrated hydrocarbons in suspected reservoir intervals can also be monitored.