They create custom-made drilling fluids

Author: Natalia RUDEVA / photo Vyacheslav SUKHODOLSKY / neft.by / 09/13/2019 /
English Translation: DeepL Translate
Natalia Smolskaya, laboratory assistant
Natalia Smolskaya, laboratory assistant
The journalists of neft.by found out what helps drillers get to productive oil reservoirs and realized that drilling mud plays an important role in conquering the depths. The liquid that resembles a thick mixture, is unattractive in appearance. But without it, it is impossible to build a well. To find out what its properties are, we went to the dissolving unit of the Backfilling Department. Here, solutions and flushing fluids are created for the drilling, repair, and restoration of wells of Belorusneft.

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
Mortar unit of the Pumping Department
More than a dozen kilometers separate them from the Backfilling Department.

This location is due to transport logistics. The unit was built in the 70s approximately in the middle of the oil fields of the Rechitsa and Svetlogorsk regions. Until 2000, they 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

High-end chemistry by individual design

In 2003, after reconstruction, three sections were put into operation at the dissolving unit: preparation of saltwater, preparation of clay and sapropel solutions, and preparation of calcium chloride. The rate of drilling grew every year, the technologies of penetration were improved, and new drilling equipment appeared. But, most importantly, such solutions were required that would meet the characteristics of the fields being developed. When creating them, it was necessary to take into account the "individuality" of each well.
Drilling fluid is a complex fluid, which contains many components in strictly defined proportions. How efficiently it is prepared and corresponds to the specified parameters depends on how effectively the wellbore will be cleaned from the cuttings. Our arsenal includes high-tech biopolymer and inhibited fluids, as well as heavy well killing fluids.
— Sergey Lutov, head of the drilling fluids workshop of the flushing fluids service service
Lutov notes that the chemistry of drilling fluids does not stand still, it is improving, reaching such heights that make the work of drillers not only effective, but also safe.

Solution innovation

If earlier only calcium chloride was used to prepare a solution with a density of up to 1.40 grams per cubic centimeter, now we are using the new MaxOil WotaSoft salt system, a heavy killing fluid based on TZhS. This helps to keep the bottom hole clean and increase 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 the light of the latest technologies and drilling speeds, it is not entirely clear whether drilling is being improved and promoted with the help of new and effective drilling fluids, or they are being "pulled up" to the level of the modern drilling process. We have to strain in the desire to understand the importance of chemistry in solution innovations. Apparently, we do not do it very well, so the master of the mortar unit Mikhail Merikov takes us to the chemical laboratory.
Laboratory equipment
Laboratory equipment
Here we are met by the engineer for drilling fluids and special fluids Maria Marinchuk, laboratory assistants Natalia Smolskaya and Nonna Drebenchuk.
There are many instruments, various flasks and test tubes, glasses, and containers with colored powders around.
Mikhail Merikov, Master of the mortar knot
Mikhail Merikov, Master of the mortar knot
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 total. The drilling fluid is prepared for each well, and its composition is adjusted depending on the manifestations of its "character". We can say that we, as pharmacists, create solutions according to individual prescriptions.
Reagents for preparing drilling fluids
Reagents for preparing drilling fluids
Well, as they say, if you don't try, you won't understand. The first operation that we were entrusted with was to determine the coefficient of foaming 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
Natalia Smolskaya, laboratory assistant
In three minutes, the ink content of the glass grows by a third. Natalia Smolskaya calculates the foaming coefficient using a special formula.
Natalia Smolskaya, laboratory assistant
Natalia Smolskaya, laboratory assistant

Ideal solutions

Our next task was to diagnose the parameters of the drilling fluid. It was required to find out how he would behave in the well - at rest, while drilling, while flowing. A rotary viscometer, which hummed monotonously on the table, helped us to determine in laboratory conditions the plastic and dynamic viscosity of the drilling fluid.
Determining the viscosity of the drilling fluid
Determining the viscosity of the drilling fluid
While the solution was spinning in the mixer, we managed 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
Tube with drilling mud

Get enough salt

We now have completed a short course in chemistry, and it is time to turn to production. Or rather, study the area where saltwater is prepared. The operator of the overhead grab crane Igor Dolgolaptev scoops up pinkish technical salt with a huge bucket and sends it to the bunker of the agitator tank with great precision.
There is about one ton of salt in the bucket. To prepare brine or cement mixing liquid, we need to dump 15 buckets. Powerful centrifugal pumps "rotate" the liquid in a closed circle. The process goes on, the salt dissolves, the liquid is saturated to a certain density. The finished mixture is settled, poured into tank trucks, and sent to the drilling rigs.
Mikhail Merikov, master of dissolving unit
The next object of our study was the site for the preparation of calcium chloride. Heavy salt calcium chloride is in white big bags.
Transportation of bulk materials in Big-Bag soft containers
Transportation of bulk materials in Big-Bag soft containers
The workers who prepare the drilling fluids were quick and dexterous in handling huge bags, very heavy judging by the tension of the hook block.
Opening of a Big Bag Soft Container
Opening of a Big Bag Soft Container
The technology is similar to that previously seen. The bag was picked up and hung over the mixing tank. Then the heavy chemicals were poured into the bunker, where they were mixed with water to the desired concentration.
Heavy fluids are needed to kill wells that have excess intra-formation pressure. The solution is pumped there to avoid emergency situations. In this area, waste-killing fluids brought from drilling rigs are still being regenerated. Once updated, 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
Territory of the mortar unit of the Pumping Department
The ready-made drilling fluid and the one that arrived from the wells are stored in the tanks. True, neither one nor the other stays for a long time.
Not a single technological operation at Belorusneft can do without flushing fluids of the Tamping Department. Drilling, reservoir stimulation, well workover, hydraulic fracturing - specialists of the Oil Well Control are needed everywhere. And most of our work is operational. For example, last night at one of the objects 120 cubic meters of heavy drilling mud was urgently required.
Alexander Astapenko, Leading Engineer of the Service for the Service of Flushing Fluids
I had to rebuild the current workflow in order to empty the containers, prepare and deliver the solution to the customer on time. Everything worked out.
In a word, we are both an ambulance and a firefighter team.
Sergey Lutov, head of the drilling fluids workshop of the flushing fluids service service
Employees of the mortar unit of the Pumping Department
Employees of the mortar unit of the Pumping Department
The dissolving unit produces more than 6 thousand cubic meters of various flushing fluids and drilling fluids per month. But the pace of drilling is growing every year. And, as Sergei Lutov says, it means that the service has no right to lag behind.

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