The journalists of neft.by have found out what helps drillers to reach productive oil reservoirs and have realized that drilling mud plays an important role in conquering the depths. The liquid, which looks like a thick mixture, is not attractive in appearance. But it is impossible to drill a well without it. To find out what its properties are, we went to the Backfilling Department's dissolving unit. This is where solutions and flushing fluids are made for drilling, repairing and restoring Belorusneft's wells.
We arrived at the second oil field of the Ostashkovichskoye field. There is a dissolving unit for the drilling fluids workshop of the flushing fluids service.
Mortar unit of the Pumping Department
More than a dozen kilometers separate it from the backfill department.
This location is due to transport logistics. The unit was built in the 70s in the middle of the oil fields of the Rechitsa and Svetlogorsk regions. Until 2000 it worked in open areas. Reconstruction of the dissolving unit made it possible to increase the volume of production of drilling fluids, reduce the time for their preparation, improve working conditions and safety of workers.
The history of the dissolving unit in photographs
Archival photo of the mortar unit at the Pumping Department
Archival photo of cisterns in the Pumping Department
Archival photo of cisterns in the Pumping Department
Archival photo of cisterns in the Pumping Department
Archive photo of the forklift at the Pumping Department
Archival photo of cisterns in the Pumping Department
High-endchemistrybyindividualdesign
In 2003, after reconstruction, three sections were put into operation at the dissolving unit: preparation of brine, preparation of clay and sapropel solutions, and preparation of calcium chloride. The rate of drilling increased every year, the technologies of penetration were improved and new drilling equipment appeared. But the most important thing was the need for solutions that would meet the characteristics of the fields being developed. It was necessary to take into account the "individuality" of each well.
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Drilling mud is a complex fluid containing many components in strictly defined proportions. How efficiently it is prepared and meets the specified parameters depends on how effectively the well is cleaned of cuttings. Our arsenal includes high-tech biopolymer and inhibited fluids, as well as heavy-duty well kill fluids.
— Sergey Lutov, head of the drilling fluids workshop of the flushing fluids service service
Lutov notes that the chemistry of drilling fluids is not standing still, it is improving, reaching such heights that the work of drillers is not only effective, but also safe.
Solution innovation
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Where we used to use only calcium chloride to produce a solution with a density of up to 1.40 grams per cubic centimeter, we now use the new MaxOil WotaSoft salt system, a heavy TZhS-based kill fluid. This helps keep the bottom hole clean and increases the density of the kill fluid to 1.70 grams per cubic centimeter.
—Sergey Lutov, head of the drilling fluids workshop of the flushing fluids service service
Impressive. But at the same time, in light of the latest technologies and drilling speeds, it is not entirely clear whether drilling is being improved and advanced with the help of new and effective drilling fluids, or whether they are being "pulled up" to the level of the modern drilling process. We have to make an effort to understand the importance of chemistry in fluid innovation. Obviously, we are not very good at it, so Mikhail Merikov, the head of the mortar unit, takes us to the chemical laboratory.
Laboratory equipment
Here we are greeted by Maria Marinchuk, engineer for drilling fluids and special fluids, and laboratory assistants Natalia Smolskaya and Nonna Drebenchuk.
Maria Marinchuk - Engineer for Drilling Rigs and Special Liquids
Natalia Smolskaya, laboratory assistant
Nonna Drebenchuk, laboratory assistant
Laboratory equipment
There are many instruments, various flasks and test tubes, glasses, and containers of colored powders.
Mikhail Merikov, Master of the mortar knot
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We have a lot of reagents. In addition to organo-mineral raw materials (sapropel), sodium chloride, known to all soda - caustic and soda ash, we use barite and carbonate weighting agents, various types of clay powders, starch reagents, defoamers and anti-seizure additives. More than 25 items in all. The drilling fluid is prepared for each well and its composition is adjusted according to the manifestations of its "character". We can say that we, as pharmacists, create solutions according to individual recipes.
Reagents for preparing drilling fluids
Well, as they say, if you don't try, you don't understand. The first task we were assigned was to determine the foaming coefficient of the drilling fluid. Natalya Smolskaya pours 400 milliliters of sapropel solution into a glass, shows how to put it into a mixer, and takes a stopwatch.
Natalia Smolskaya, laboratory assistant
In three minutes, the color content of the glass increases by a third. Natalia Smolskaya calculates the foaming coefficient using a special formula.
Natalia Smolskaya, laboratory assistant
Ideal solutions
Our next task was to diagnose the parameters of the drilling fluid. We needed to know how it would behave in the well - at rest, while drilling, while flowing. A rotary viscometer, humming monotonously on the table, helped us determine the plastic and dynamic viscosity of the drilling fluid under laboratory conditions.
Determining the viscosity of the drilling fluid
While the solution was spinning in the mixer, we were able to determine the content of sand in the sapropel solution, see the process of its water loss through paper filters, weigh the separated saline filtrate on an analytical balance, examine a variety of samples of chemicals used to prepare solutions and process fluids.
Tube with drilling mud
Get enough salt
Now that we have completed a short course in chemistry, it is time to move on to production. Or rather, to study the area where salt water is prepared. Igor Dolgolaptev, the operator of the overhead grab crane, scoops up pinkish industrial salt with a huge bucket and sends it to the bunker of the stirring tank with great precision.
Igor Dollagtev, driver of a bridge grab crane
Loading of technical salt
Discharge of technical salt
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There is about one ton of salt in the bucket. To make brine or cement mixing liquid, we need to empty 15 buckets. Powerful centrifugal pumps "spin" the liquid in a closed circuit. The process continues, the salt dissolves, the liquid is saturated to a certain density. The finished mixture is settled, poured into tanker trucks and sent to the drilling rigs.
—Mikhail Merikov, master of dissolving unit
The next object of our investigation was the site where calcium chloride is prepared. The heavy salt calcium chloride is in white big bags.
Transportation of bulk materials in Big-Bag soft containers
The workers preparing the drilling fluids were quick and dexterous in handling the huge bags, which were very heavy judging by the tension of the hook block.
Opening of a Big Bag Soft Container
The technology is similar to the previous one. The bag was picked up and hung over the mixing tank. The heavy chemicals were then poured into the bunker where they were mixed with water to the desired concentration.
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Heavy fluids are needed to kill wells with excessive intra formation pressure. The solution is pumped there to avoid emergency situations. In this area, waste kill fluids brought in from drilling rigs are still being regenerated. Once upgraded, they are ready for further use.
—Mikhail Merikov, master of dissolving unit
No right to fall behind
We go to the territory of the dissolving unit.
Territory of the mortar unit of the Pumping Department
The finished drilling fluid and the fluid coming from the wells are stored in the tanks. It is true that neither one nor the other remains for a long time.
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Not a single technological operation at Belorusneft can do without the flushing fluids of the Tamping Department. Drilling, reservoir stimulation, well workover, hydraulic fracturing - oil well control specialists are needed everywhere. And most of our work is operational. Last night, for example, 120 cubic meters of heavy drilling mud were urgently needed at one of the facilities.
—Alexander Astapenko, Leading Engineer of the Service for the Service of Flushing Fluids
I had to re-engineer the current workflow to empty, prepare and deliver the solution to the customer on time. It all worked out.
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In a word, we are both an ambulance and a fire team.
—Sergey Lutov, head of the drilling fluids workshop of the flushing fluids service service
Employees of the mortar unit of the Pumping Department
The dissolving unit produces more than 6 thousand cubic meters of various flushing and drilling fluids per month. But the pace of drilling is increasing every year. And, as Sergei Lutov says, this means that the service has no right to lag behind.