Low Pressure Bottom Hole Sample Collection For Complex Water Characterization

Transcription

1 Low Pressure Bottom Hole Sample Collection For Complex Water Characterization

2 Biography Todd Zurowski Todd Zurowski Bsc. Mechanical Engineering at U of C Began with AGAT 2012 as project engineer 2014 took on the roll of technical adviser Member of the following societies APEGA CHOA Canadian Heavy Oil Association SPE Society of Petroleum Engineers Outdoor Enthusiast Biking Skiing Hiking

3 Agenda 1) Bottom Hole Sampling What is it? 2) Advantages 3) Tool specifications 4) Sample Reception 5) Common Analysis 6) Past Projects

4 Bottom Hole Water Sampling What is it? Collecting fluid from the bottom of a well bore to obtain a sample as representative as possible to that of the formation Uses a slickline or wireline to lower the tool to the desired depth Tool s sample chamber opens after a specific period set on surface

5 Surface Sampling vs Bottom Hole Sampling Table 1 Surface Sampling Pros Inexpensive method of sampling collection Can collect large volumes relatively quickly Only 1 or 2 field technicians needed Variety of sample container Cons Require surface equipment (ie Separators) and in some cases bottom hole pumps Need onsite preservation due to short hold times Some volatiles can be lost Hard to determine GWR/GIS

6 Surface Sampling vs Bottom Hole Sampling Table 2 Bottom Hole Sampling Pros No need for surface or bottom hole equipment Collects pressurized samples No flashing of volatiles in the wellbore Preservation can be done in lab Cons Requires slickline or wireline trucks More coordination required Can be more expensive Need trained technicians to program tool Can collect large volumes of sample Uses inert containers

7 Bottom Hole Water Sampling Advantages Collection of a pressurized fluid Can be operated at low pressure (~10psi+) contains dissolved gases, metals, salts and any volatile components No need for downhole equipment to be installed (ie Pumps) No need for surface equipment to deal with produced fluids (ie Separators) No onsite transfers / preservation needed Sample can be shipped to the lab without preservation needed onsite

8 Bottom Hole Sampler Specifications Table 3- Tool Specifications Parameter Minimum Pressure Maximum Pressure Tool Specifications 10 Psi Psi Maximum Temperature 150 C Outer Diameter 1.75 Inches

9 Bottom Hole Water Sample Collection Efficiency Table 4 - Sample collection efficiency at 10 psi hydrostatic pressure Trial Number Total Chamber Volume (cc) Sample Volume Collected (cc) Fill Efficiency (%) Average cc 96.7 %

10 Sample Reception In The Lab Opening pressure of cylinders are checked for QC If pass QC the samples move on Perform Single Stage Flash Obtains Gas to Water ratio (GWR)

11 Single Stage Flash Table 1 Single Stage Flash

12 Sample Reception In The Lab Fluids are collected Water sent for analysis Gas sent for analysis

13 Bottom Hole Sample Analysis Water Chemistry 3 different analysis covering different parameters Gas analysis 3 different gas analysis can be performed for the purpose of reporting to different fractions Trace sulphur and hydrogen sulphide in water and gas Dissolved and total Metals Alberta Tier 1 or Customized Hydrocarbon content in water BTEX F1-F4

14 Common Tests for Water Chemistry Water Chemistry Routine, Extended, Complete Hydrogen Sulphide Dissolved and Total Metals Alberta Tier 1 or Customized Hydrocarbon Content BTEX F1-F4

15 Water Analysis Packages Once a set of representative samples have been obtained, a water analysis must be completed prior to making any calculations or conclusions. Complete Water Analysis ph, H2S, Density, Resistivity, Salinity and Total Alkalinity Refractive Index Cations (Na+, K+, Ca2+, Mg2+, Fe2+, Ba2+, Sr2+) Anions (Cl-, HCO3-, SO42-, CO32-, OH-, Br-, I-) Total Dissolved Solids (experimental and calculated)

16 Water Analysis

17 Cation Determination Atomic Absorption Measures absorption 2300 C to 2700 C Higher detection limits Fewer dilutions Limited metals Inductively Coupled Plasma -OES or MS Measures emissions 6000 C to 10,000 C Lower detection limits More dilutions Most elements

18 Anion Determination Titration Wider detection range Higher detection limits Fewer dilutions Ion Chromatography Narrower detection range Lower detection limits More dilutions

19 Common Gas Analysis Gas Composition up to C15+ Report to C7+, C10+ and C15+ Analysed by a GC equipped with a Thermal Conductivity Detector (TCD) Trace Hydrogen Sulphide Trace Sulphur Isotopes Carbon, Hydrogen Sulphur and Oxygen

20 Solid Analysis Particle Size Determination Sieve and Laser Can perform either of the different types or a combination of both Beckman Coulter LS Alternative for Low solids SEM Mineralogy Methylene Blue Index (MBI) Sonication using Sodium bicarbonate NaOH for ph adjustment X-Ray Diffraction Bulk and Clay

21 Recent Projects at oilsands mine Problem Trying to determine the quality of their aquifer water without having surface or downhole equipment installed Low Pressure Bottom Hole Water Sampling Many different parameters are being measured with focus on GIS and H2S concentration in the gas and water Generic Oil Sands

22 Recent Projects at oilsands mine Sampling Plan Sample 5 different wells to determine variation of water throughout their property Sampled 1 well from different depths to see if there was a variation observed from the top and bottom of the hydrostatic water chamber

23 Conclusion Can achieve very low pressure sampling Obtain pressurized fluids from downhole with no downhole or surface equipment Can analyze volatile components Can collect large amounts of samples to achieve a large scope of work. Anything worth doing, is worth doing right. Hunter S. Thompson

24 AGAT Laboratories Review Team Reservoir Engineering Acknowledgments

25 AGAT Laboratories QUESTIONS? Contact Information: Todd Zurowski