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Solids Dewatering, Transport, and Disposal - Goals and Objectives of FSM Module 9 (B-FSM-152)

We now move on to Facilities Sand Management training module FSM-M9 pertaining to solids (slurry) dewatering, transport, and disposal. The module goals include the following items;

  • Clearly define dewatering, transport, and disposal and their processes in a solids handling system
  • Show that design of the entire solids handling system should start with clear identification of the disposal route
  • Provide guidelines for combining steps and simplifying overall design

For those that may have recently started reading this blog series I will restate some of the background information so that everyone understands the basis of this technology series.

Facilities Sand Management (FSM)

In this series, which started July 28, 2017 with blog post B-FSM-001, I am covering the entire contents of my training course entitled Facilities Sand Management. This is a training course originally designed for the Society of Petroleum Engineers (SPE) and has been given both at SPE and private-corporate events around the world. This is a 2-3 day course that covers both the design and operating philosophy, as well as unit-operations, for handling sand and solids in oil & gas production at the operating facilities. Some basic assumptions are as follows;

  • Facilities: oil & gas upstream surface/subsea equipment for separation, cleaning, and energy addition (e.g. wellhead to custody transfer)
  • Sand: tiny loose pieces of rock
  • Management: to handle or direct with a degree of skill

FSM is not simply a waste stream treatment exercise…it is a critical Flow Assurance issue.

The stated objective is to increase / maximize hydrocarbons production…while reducing / minimizing operating costs.

Step Three of the Five Steps of Sand Management

The Five Steps of Sand Management have been covered in previous blog posts – for example B-FSM-034 and B-FSM-040.

Dewatering, transport, and disposal are Steps 4 and 5 in this methodology and were introduced in blog posts B-FSM-038 and B-FSM-039. These are necessary steps to properly get the removed sand away from the facility and not hold-up production.

This series of posts will cover the why, what, and how of solids dewatering, transport, and disposal.

References:

  1. Rawlins, C.H. and Wang, I. 2001. “Design and Installation of a Sand-Separation and -Handling System for a Gulf of Mexico Oil Production Facility”. SPE Production and Facilities, August, pp. 134-140. https://doi.org/10.2118/72999-PA
  2. Rawlins, C.H. 2019. “Enhanced Production Through Surface Facilities Sand Management.” SPE Distinguished Lecturer presentation. Link here

Next week I will start with the role of dewatering, transport, and disposal – including the 80/20 rule.

Sand Cleaning – Key Items and Technical Paper References (B-FSM-151)

This post concludes the discussion on offshore sand cleaning. This series was started with post B-FSM-133.

Key Takeaway Items from Sand Cleaning Module

  1. Only oil is practically cleaned to allow overboard disposal
  2. Sand cleaning systems employ mechanical scrubbing
  • Heat and surfactants may be added but typically not used
  1. Cyclonic Cleaning System
  • Uses mechanical scrubbing (shear, abrasion, and attrition)
  • Closed loop cleaning cycle – eductors and cyclones
  • Must match input/output to overall solids handling
  1. Sand cleaning is a system not an off the shelf product therefore needs proper process design

References:

  1. Amani, H., “Evaluation of Biosurfactants and Surfactants for Crude Oil Contaminated Sand Washing”, Petroleum Science and Technology, Vol. 33, 2015, pp. 510-519.
  2. Buckley, J.S., Fan, T., “Crude oil/brine interfacial tensions”, Petrophysics, Vol. 48, No. 3, June 2007, pp. 175-185.
  3. Dai, Q., Chung, K.H., “Bitumen-sand interaction on oil sand processing”, Fuel, Vol. 74, No. 12, 1995, pp. 1858-1864.
  4. Davis, E.A., Lien, B.K., “Laboratory Study on the Use of Hot Water to Recover Light Oily Wastes from Sand”, U.S. EPA Project Summary Report EPA/600/SR-93/021, May 1993.
  5. Garcia, J.A., “A System for Removing and Disposing of Produced Sand”, Journal of Petroleum Technology, April 1974, pp. 450-454.
  6. Hess, M., Sinker, A., Rawlins, H., “Treatment of Solids at Oil Production Installations”, paper presented at IBC Conference on Meeting Environmental Standards for the Offshore Industry, Aberdeen, UK, December 1997.
  7. Hodson, J.E., Childs, G., Palmer, A.J., “The Application of Specialist Hydrocyclones for Separation and Clean-Up of Solids in the Oil and Gas Industry”, paper 7590 presented at the 26th Annual OTC, Houston, TX, USA, 2-5 May 1994.
  8. Melchor, A.E., da Costa, A., Rodriguez, C., Pena, J.R., “E&P Waste Management in the Orinoco Delta”, SPE Drilling & Completions, September 2002, pp. 164-173.
  9. Murray, A.J., Kapila, M., Ferrari, G., Degouy, D., Espagne, B.J-L., Handgraaf, P., “Friction-Based Thermal Desorption Technology: Kashagan Development Project Meeting Environmental Compliance in Drill-Cuttings Treatment and Disposal”, paper 116169 presented at the SPE Annual Technical Conference and Exhibition, Denver, CO, USA, 21-24 September, 2008.
  10. Quaishi, S., Bussmann, M., Acosta, E., “Capillary curves for ex-situ washing of oil-coated particles”, Journal of Surfactants and Detergents, Vol. 18, 2015, pp. 811-823.
  11. Smith, P.G., van de Ven, T.G.M., “The Separation of a Liquid Drop from a Stationary Solid Sphere in a Gravitational Field”, Journal of Colloid and Interface Science, Vol. 105, No. 1, May 1985, pp. 7-20.
  12. S. Patent 4347118, “Solvent Extraction Process for Tar Sands”, August, 31, 1982, assigned to Exxon Research & Engineering Co.
  13. S. Department of Energy, National Energy Technology Laboratory, “Drilling Waste Management Information System: Fact Sheet – Thermal Treatment Technologies”, September 2, 2015, http://web.ead.anl.gov/dwm/techdesc/thermal/.

Next week I will start the module on Dewatering-Transport-Disposal.

Sand Cleaning – Integration with Solids Handling and Disposal (B-FSM-150)

The graphic below provides some introductory sizing data for building a sand cleaning system.

References:

  1. Rawlins, C.H. and Wang, I. 2001. “Design and Installation of a Sand-Separation and -Handling System for a Gulf of Mexico Oil Production Facility”. SPE Production and Facilities, August, pp. 134-140. https://doi.org/10.2118/72999-PA
  2. Rawlins, C.H. 2019. “Enhanced Production Through Surface Facilities Sand Management.” SPE Distinguished Lecturer presentation. Link here

Next week I will recapture key items and technical paper references.

Sand Cleaning – Integration with Solids Handling and Disposal (B-FSM-149)

The sand discharged from the cleaning loop must be handled and disposed. Solids dewatering, transport, and disposal will be covered in a future post series – and the graphic below show the key items that should be addressed.

References:

  1. Rawlins, C.H. and Wang, I. 2001. “Design and Installation of a Sand-Separation and -Handling System for a Gulf of Mexico Oil Production Facility”. SPE Production and Facilities, August, pp. 134-140. https://doi.org/10.2118/72999-PA
  2. Rawlins, C.H. 2019. “Enhanced Production Through Surface Facilities Sand Management.” SPE Distinguished Lecturer presentation. Link here

Next week I will cover specific system equipment sizing.

Sand Cleaning – Physical/Process Effects (B-FSM-148)

Process and physical conditions of the sand cleaning system operation all have an effect on efficiency of sand cleaning. The most common items are listed and detailed below.

Temperature: increasing promotes oil-sand separation

  • Decreases oil-water IFT, and increases magnitude of “-” charge on silica, decreases oil viscosity – all which promote oil-sand separation
  • Recommend to change from 25° to 50°C if used

Particle Size: increasing size promotes oil-sand separation

  • Small particles have higher surface area and harder to clean
  • Easier to clean >100 µm particles

Scrubbing Intensity: increasing promotes oil-sand separation

  • System should promote We>100:    𝑊𝑒=(𝜌𝑉^2 𝑑)/𝛾
  • Increase velocity between continuous phase and particle improves oil removal

Time: longer wash time in loop improves cleaning

  • Time of slurry in intense scrubbing zone (jetting unit, pipe, eductor, sand cleaning cyclone) varies from 1-3 minutes
  • Total loop recirculation time is 30 minutes, typically 1-3 cycles sufficient
  • Loop is tuned during commissioning – samples take periodically during initial cleaning to determine cleaning cycle duration and outlet OIW

References:

  1. Rawlins, C.H. and Wang, I. 2001. “Design and Installation of a Sand-Separation and -Handling System for a Gulf of Mexico Oil Production Facility”. SPE Production and Facilities, August, pp. 134-140. https://doi.org/10.2118/72999-PA
  2. Rawlins, C.H. 2019. “Enhanced Production Through Surface Facilities Sand Management.” SPE Distinguished Lecturer presentation. Link here

Next week I will cover how to integrate the system with solids handling and disposal.
 
 
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