The present article considers the issue of research and development of peat-alkaline fluid with high inhibitory ability. Test fluids formulas are given for the required rheological properties. Application of developed peat-alkaline fluid allows for trouble-free wells drilling within intervals in clay deposits.
The country has recently increased the quantity of deep wells drilling and geological and technical conditions for their targeting have complicated. This increases quality requirements for drilling and grouting fluids, as well as for process fluids used during well repair.
Caustobioliths - natural organogenic materials (sapropel, peat, brown coal, etc.) are promising for the preparation of drilling fluids. The authors are actively involved in the development of new materials based on peat. In particular, the peat-alkaline fluid for wells drilling in the intervals of clay and permafrost (MMP) rocks was developed, including peat, alkaline modifier, inhibitor, flocculant and water. In contrast to the closest analogue it additionally comprises of a fluid loss reducer and antifoaming agent, and as fluid loss reducer the Polydia polymer is used and as antifoaming agent – antifoamer Mogutov MAC 200M.
Peat drilling fluids are environmentally friendly, easy to clean from mud, after use, they can be used for land reclamation.
The peat includes a range of substances very valuable from the position of drilling fluids - humic acid, hemicellulose, starch and pectin, bitumen, etc. and lignin. Peat humate agents are already applied for drilling fluid properties control due to their availability, low cost of raw materials and ease of preparation.
In addition, the authors have developed a viscoelastic composition (VEC) during repair works in the wells, including peat, pottasic alkaline modifier, potassium chloride, polymer, weighting agent, antifoaming agent and water.
A special feature is the ability of VEC to degrade over time; VEC is adjusted by changing the ratio of ingredients, or media pH, or by entering the destructor under shear deformations. After the destruction the composition has a minimum viscosity (1.5–2 cps), but retains a minimum filtering and completely removed from the reservoir after simple processing methods.
rock scree, well walls collapse, peat alkaline fluid, wells drilling, clay rocks.
Kustyshev A.V., Leontyev D.S. Investigation of the peat-alkaline fluid properties for wells drilling in argillaceous rocks (In Russ.). Territorija «NEFTEGAZ» = Oil and Gas Territory, 2016, No. 3, pp. 56–62.