GEOSYNTHESIS ENGINEERING

Development and service of drilling fluid

Witer-II is designed for penetration of production zone and completion, drilling in emergency areas of any complexity, overhaul of wells also used as a special fluids for well completion.

A distinguishing feature of IEDM is to use a hydrocarbon liquid as a dispersion medium, and water or salt solutions as a discontinuous phase.

The filtrate solution is represented by the hydrocarbon liquid, which eliminates problem of solid stability loss on the walls of the well and the swelling of clay minerals in the reservoir due to their hydration. This creates optimal conditions for trouble-free drilling and high quality of productive horizons opening.

HISTORICAL REFERENCE

There were two major science centers for developing hydro-carbonate based drilling fluids in USSR, where Ukrainian specialists (Rozengaf A.G., Luban V.Z., Dopilko L.I. etc.) were active participants in such place as, Moscow, MINH and GP named after Gubkin, with mentoring of Ph.D. Muchilin L.K. and in Kiev, in UkrGIPRONIIneft (Tokunov V.I. and Heifec I.B.). Hydro-carbonated systems were researched a lot in Poltavska oblast (Sagaydakskaya, Radchenkovskaya, and Brateshkinskaya regions).

Unfortunately, in 80 years, works in this direction were interrupted. Tom had a lot of reasons, including environmental and fire hazard, high cost, etc. But the most important, perhaps, was a strong competition from, at the time the new, polymer drilling fluids largely not inferior to OBM.

In 1980s, unfortunately, works in this direction were interrupted. That was a result of many reasons, the most valuable of those are environmental and fire hazard, high cost, etc. Probably, the most important was a strong competition from, polymer drilling fluids, which were new for that time, largely not inferior to OBM.

We had predicted this situation. Therefore, we had worked to create our own IE recipes since 2013. Because of the hostilities, we were forced to terminate our relationship with RGU (RNU (Russian National University)) named after Gubkin, so our partners in this work was the Polish enterprises, PSPW company (Krosno) and the Oil and Gas Institute (Krakow). As a result, we have got new invert emulsion Witer-II.

ADVANTAGES:

Determined by the nature of the hydrocarbon and the filtrate and minimal contact with the aqueous phase.

Witer II system provides a high degree of stability of a wellbore drilled out and a minimal dispersion of the clay slurry.
Virtually eliminates the technogenic pollution of productive horizons, associated with hydration, swelling and dispersing the clay material collectors. Mineralization medium does not affect the properties of the emulsion solution.
High lubricating and anti-stuck properties. A broad range of densities.
High penetration rate, a sharp decrease of the time required to study and calibrate the wellbore.

LIMITATIONS

  • During the drilling process it is necessary to control the process parameters of the drilling fluid accurately, it is electrical stability and the ratio of aqueous and hydrocarbon phases. It is also necessary to monitor solids control; constant work of cleaning system, and centrifugal plants.
  • Presented special demands on preparation technology and components of the emulsion. Requires special equipment and training.
  • There are negative influence on emulsion parameters that made by, the excess supply of the aqueous phase, particulate contamination of mud cuttings clay solids, the high temperature in the well.
  • Intensive absorption of IEDM can be possible when there are not enough fillings to make filter cake or if they have irregular component composition.
  • Nowadays, the thermal stability of Witer II is set at 140°C. There is a technical possibility to further increase the thermal stability limit. We continue researching and testing emulsion.
  • Minimum value of electrical stability when deeping of the well has to be stopped is 200 V.
  • All oil based muds, including invert emulsion, are characterized by high toxicity, flammability and high cost. Harm to the environment is possible if special facilities were not abode.
  • Conduction of electric logging is impossible in inverted emulsion system.

COMPOSITION AND OPTIONS WASHING SYSTEM

Drilling fluid composition:

  • Diesel oil 80-90% of the total volune of fluid - Dispersion medium;
  • Water 20-10% of the total volume of fluid - Water disperse phase;
  • E-4 6-7% Emulsifier 1;
  • E-5 2-3% Emulsifier 2;
  • H-1 1-3% Water-repellent solid phase;
  • F-1 2-4% Filtration loss agent;
  • Organophilic bentonite 5-7% Solid stabilizer, filler;
  • CaCl2 25-30% on water volume - Mineralizer aqueous phase;
  • M-25 10-15% Carbonate colmatant;
  • K-200 1-2% Organic colmatant;
  • CaO 1-2% Neutralizer of free organic acids, pH adjusters;
  • Hydrophobic barite - weight material up to the required density.

Parametrs of drilling fluid:

  • Density 1020-1900 kg/m3,
  • Funnel viscosity 80-150 s,
  • Gel 30/40-65/70 dPa,
  • Filtration loss 0.5-2.5 cm3/30 min.,
  • HPHT filtration loss 140C 10-15 cm3/30min,
  • PV 20-60 mPa*s,
  • YP  70-150 dPa,
  • Electrical stability -> 300 V.