WO2018070858A1

WO2018070858A1 - Polymeric sea water-based fluid containing potassium chloride for onshore and offshore well drilling

Info

Publication number: WO2018070858A1
Application number: PCT/MX2017/050016
Authority: WO
Inventors: Carlos BARAJAS HERNÁNDEZ
Original assignee: Tecnología Integral En Fluidos De Perforación, S.A. De C.V.
Priority date: 2016-10-13
Filing date: 2017-10-27
Publication date: 2018-04-19
Also published as: MX2016013496A

Abstract

The invention relates to a polymeric sea water-based fluid containing potassium chloride for onshore and offshore well drilling, wherein the fluid is designed for drilling formations with a low or medium clayiness, but is not limited to this type of well formation if the circumstances justify it. In the preferred embodiment of the invention, the fluid is used for drilling the clayey zones with the high-performance, polymeric sea water-based fluid containing potassium chloride. The present invention fulfills the rheological technical requirements for achieving cuttings transport and suspension, the control of the filtering, lubricity and inhibition of clays. The fluid according to the invention is mainly composed of sea water and polymeric liquid products of new-generation technology, which are high-performance, and which are simple to prepare and quick to homogenise, thereby minimising the logistics of ships and ensuring the continuous supply of the fluid volume during the drilling in order to prevent non-productive times, thereby guaranteeing the lowering of the casing pipes in the estimated time, without operational logistical delays.

Description

POLYMERIC SEA WATER BASED FLUID WITH POTASSIUM CHLORIDE FOR PERFORATION OF GROUND WELLS AND WELLS COSTA AFUERA

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the application in the technical field of drilling of oil, geothermal and similar wells, of the Tsimin, Xux, May, Bolontiku, Kab and Xanab fields of the Abkatun Production asset; and the Chuhuk, Kuil, Pool, Chuc, Homol, Onel wells of the Litoral Production asset; as well as the Cantarell asset, the wells, Ek, Balam, Ixtoc, Kambesah, Ku Maloob Zaap, Yaxche, Kax and Uech assets located in the waters of the Gulf of Mexico, whose formations are considered moderately reactive by the clays present in these strata, the which are considered low and medium temperature wells. During the drilling of hydrocarbon producing wells, to reach the depths where the oil and gas deposits are located, several extracts of the earth's crust are drilled, these extracts are several terrestrial layers, which have different characteristics in the composition of the rock, pressures and temperatures, and to achieve these objectives drilling fluids are used, well drilling is done both in land and marine locations. The selection and design of the fluids should be carried out with the purpose of avoiding problems and operational risks, reducing operating costs by shortening the drilling times, increasing and extracting the production of hydrocarbons.

During the drilling of the surface blocks of the Gulf of Mexico, where the POLYMERIC SEA WATER BASE WITH POTASSIUM CHLORIDE fluid, referred to herein as SP-KCL® for practicality purposes, will be used, the stages range between 50.0 and 1000 , 0 m deep. The rock formations that are present are mainly formed by clays with sand, with working densities in the range of 1.08 to 1.40 g / cm ³ or more, depending on the well. The clays present are of low and medium reactivity of 15.0 to 50.0 meq / 100 g of clays. The background temperature of these formations ranges from 50.0 to 90.0 ° C. During the drilling of these stages, the main problems are: Maintain the stability of the well walls, since the formations are highly collapsible due to the presence of high percentages of battered sands. For this phenomenon, a fluid with clay inhibition is required, due to the presence of the latter's hydration, which causes swelling, dispersion, embolisms, colloidal solids, torque and drag problems, to mention. In addition, due to the diameters of the augers used in these stages, normally 26.0 "in diameter, it is necessary that the designed fluid has a good cleaning in the well, according to the operating conditions and advances.

Potassium chloride-based drilling fluids are used in areas where the chemical alteration of clays is required to be limited by interaction with drilling fluids. The potassium ion is used as an inhibitor ion due to the exchange of ionic bases of potassium ions with sodium and / or calcium ions between the clay layers and by fixing the potassium ion in the crystalline network of inflatable clay minerals. Another factor by which the potassium ion is used as an inhibitor is due to the fact that its molecular geometry is better coupled in the crystalline networks of the clay due to its size, compared to the sodium ion and the calcium ion. The fluid of the present invention is not limited to only clay wells, but to any type of well where the operation justifies it. BACKGROUND OF THE INVENTION

Since years of 1970, an infinity of water-based drilling fluids has been tested as a continuous phase to drill in hydrocarbon producing fields in Mexico, in the land area as in the marine area of the Gulf of Mexico, in the Tertiary in the Times of the recent Pleistocene and Miocene, among others. In some cases, these areas comprise depths from 50.0 m, 1000.0 m and up to 1800.0 m, this drilling stage is commonly identified with the diameter of the auger with which it is drilled 26.0 "in diameter and Others: The types of rock are sandstones, clays, shellfish fragments, bentonite shales, etc. The use of water-based fluids has evolved over time, in the beginning simple fluids based on viscosifiers, filtration reducers were used , dispersants and alkalizing agents, and as a barite (barium sulfate) densifier, but unfortunately these fluids were not the drilling solution of these stages of 26.0 "and 17.0" in diameter, too many operational problems were already present in drilling, increasing the degree of risk and dangers for operators in these areas, high environmental impact, longer drilling times and, in addition to all these factors, cost-benefit was greatly affected or of the well.With these fluids there was no mechanical stability of the walls of the well, the chemical inhibition of the clays characterizing the wells was missing, as too many uncalibrated. The technology of water-based fluids was developed until today with water-based fluids based on polymers, such as the Sea Water Base with Potassium Chloride fluid, called SP-KCL®. This fluid is designed to fulfill the main functions of drilling fluids in general, such as: Clipping.

Control of training pressures.

Suspend drilling cuts.

Seal permeable formations.

Maintain hole stability.

Cool, lubricate and float the drill string.

Transmit hydraulic energy to the auger and to the assembly of drill rigs. Provide a suitable means for taking electrical records.

Corrosion control.

Facilitate the cementation and completion of the well.

Minimize damage to the deposit.

Minimize the environmental impact.

Minimize the time scheduled for drilling the well.

Safe operation and lower risk of toxicity and safety for operators.

Carrying the perforated cuts to the surface, all fluid must transfer the perforations to the surface by means of the properties provided by the chemical and polymeric materials that provide the viscosification, if this function is not fulfilled, the well can be lost due to problems Cleaning or hauling. Control of the formation pressures, if the formation pressure is not controlled the well can be started or it can suffer a loss of total circulation of the fluid, with its consequent collapse of the well. The above is avoided with different chemical materials of the fluid such as viscosifiers to maintain high molecular weight solids (Barite), in suspension and thus have a homogeneous fluid controlling the formation pressures with The work density of the fluid. As stated above, the fluid must suspend drilling cuts and solids that the fluid contains in a homogeneous manner during the stoppages of fluid circulation, which are required by failures or adjustments in the drilling decisions. The different rocks to be drilled have different physical and chemical characteristics, among those characteristics are the porosity and permeability of rocks and / or arenas; who have greater permeability and porosity than shales or clay rocks. The fluid invades these porous areas so that the fluid is required to generate a layer or coating that allows these permeable areas to be sealed, and with this control the problem of differential sticking that occurs in drilling operations is avoided. Maintain the stability of the perforated hole, the wells are protected with casing pipes so that they do not collapse, but the area of the open hole in drilling must also be protected and this is done with the drilling fluid with chemical wall stabilizing materials that function is to keep the well stable without collapsing. Cool and lubricate the auger with the constant pumping of the circulating fluid, in drilling of wells the auger and the assembly of tools are used, these work with good functioning when you have a drilling fluid in good optimal conditions, resulting in a better Progress in the perforated meters and the service times are reduced with the SP-KCL® fluid, with an optimization reflected in the times in a 40.0% benefit in drilling times with other fluids. The SP-KCL® fluid is designed with seawater, so it has in its composition enough inorganic salts that are a good means to propagate the electrical signals of the geophysical records, since these are used to take important information in drilling of wells. Secondary corrosion control is carried out with alkalizer, bitter gas controller and amine corrosion inhibitor, which is important to protect the pipes, equipment and tools used in drilling operations. When you have a good drilling fluid this is reflected in the activities of the other operations involved to drill a well, such as the cementing of casing pipes and the completion of the wells, the cements will act with better adhesion if the enjarres of Drilling fluids are thin and easy to remove. When drilling fluids are designed, they must comply with the current well cleaning standards, so it must be designed with chemical materials that are soluble and not reactive with 15.0% hydrochloric acid, with this control the plugging of the matrix of the producing deposits. This fluid has a low toxicity compared to others, the chemicals used in this fluid reduce the risk of exposure by design, coupled with the above physical presentation of each chemical component of the fluid allows a more agile and safe operation for the personnel operating the well and preparing the fluid. And finally using oil-free water-based fluids, since accidents with a massive effect can occur and can cause catastrophic spills to the environment, with the fluid designed to comply with these regulations, the environmental impact can be mitigated with drilling fluids. DETAILED DESCRIPTION

Brief description of the figures.

Figure 1 depicts the production zone drilling stage, where the fluid of the present invention is applied. Figure 2 illustrates the results of the linear fluid expansion percent test of the present invention.

Detailed description of the invention

It is a seawater-based drilling fluid, formulated based on polymeric chemicals and clay inhibitors in liquid and solid state of new technological generation with high performance, easy addition and rapid mixing, preparation and homogenization that minimizes time of its preparation, emphasizing the drilling of the low and medium clay formations of the surface blocks on the Gulf of Mexico platform. The preferred embodiment for purposes of explaining the operation of the fluid of the present invention relates to clay wells, however, the present invention is not limited to only clay wells, but to any type of wells.

The system that fulfills the main functions required of drilling fluids, in addition to providing high control of inhibition of both swelling and dispersion of clays, and the encapsulation of colloidal solids, due to its polymeric character of its materials with which It is composed in its initial formulation, it is a base fluid that does not contain solids, and can be densified with barium sulfate to working densities that are used in perforated stages in oil fields. It provides excellent transportation and cleaning of the drill cuttings well, and gives global compliance in environmental matters. The fluid with chemical materials, polymers and potassium chloride was developed to stabilize water-sensitive shales by inhibition with potassium ion. The inhibitory character of this fluid minimizes the hydration of shales, which minimizes the swelling of the clays in the open hole of the well, this in turn avoiding the embolamiento of the augers and stabilizers, the dispersion and the delectable clays, and the reduction of permeability in productive areas. The potassium chloride fluid uses the potassium chloride salt (KC1) as the main source of potassium ions for ionic inhibition. This fluid is effective because it uses polymers for the encapsulation of reactive colloidal solids.

Polymers such as the filtrate reducer and the inhibitor of slippery clays and well stabilizer of hole walls are designed to be used for encapsulation. These polymers cover the cuttings and exposed shales, limiting the interaction with water. Since some shales are more sensitive to water than others, the concentration of KC1 required to inhibit these shales will vary. During drilling operations, shale cuts should be continuously monitored to determine inhibition. If the concentration of KC1 in the fluid is not sufficient, shale cuts will be soft and fluffy. If the concentration of KC1 is sufficient, these cuts will maintain their integrity. The Fluid is designed with the following chemical materials: Sea water Continuous phase

Alkalizing Amines

Inorganic salt Mechanical clamp inhibitor KC1

Amines and glycol based inhibitor Chemical clays inhibitor Partially hydrolyzed polyacrylamide in suspension Dispersion clays inhibitor

Polyanionic cellulose in suspension Filtration reducer

Biopolymer in suspension Polymeric viscosifier

Calcium Carbonate Mesh -70 Bridging Agent

Calcium carbonate Mesh -200 Bridging agent Calcium carbonate Mesh -325 Bridging agent

Densifying Barium Sulfate

In Figure 1, the oil stratigraphy where the deep drilling operation of oil wells and the application of the fluid to POLYMERIC SEA WATER BASE WITH POTASSIUM CHLORIDE called SP-KCL®, obtained with the process of the present invention, at an average depth of between +250.00 to 1,360.00 m vertical below sea level, with operating temperatures at drilling between 50.00 ° C to 90.00 ° C, with operating pressures background of +1,935.00 Kg / cm ² . Likewise, in Figure 1 you can see the Stage (E) of drilling the production area where the seawater base fluid obtained with the process of the present invention is applied. More specifically, the fluid of the present invention has the following formulation and concentrations: Table 1. Formulation, product concentrations.

CONCENTRATION PRODUCT

Seawater Adjust to 1.00 m ³

Amines 0.5 to 6.00 L / m ³

Potassium Chloride 5.00 to 120 kg / m ³

Inhibitor based on amines and glycol 1.00 to 8.00 L / m ³

Partially hydrolyzed polyacrylamide 0.5 to 8.00 L / m ³

Polyanionic cellulose in suspension 0.5 to 24.00 L / m ³

Biopolymer in suspension 0.5 to 25.00 L / m ³

DENSIFYING MATERIAL 115.28 kg / m ³ The technical evidence that the fluid of the present invention is functional and can be carried out is indicated in the following laboratory tests to evaluate our fluid called SP-KCL®, POLYMERIC SEA WATER BASE WITH POTASSIUM CHLORIDE, for formations of the Lower Eocene, Lower and Upper Paleocene of the fields of the Abkatún-Pol-Chuc asset, which present conditions of total loss of circulation and manifest the presence of clay bodies. This was done based on the technical specification P.7.0841.01, Petroleum exploration - Shale inhibitor water based systems used in drilling oil wells - Specifications and test methods; and with samples of formation of fields with clays of high and medium reactivity.

Once the base formulation was prepared, the mixture was stabilized for 16.00 h @ 65.00 ° C. Subsequently, we proceeded to evaluate the physicochemical properties such as rheological and thixotropic behavior, filtering and the pH of the system. The base formulation is that indicated in the previous table.

The following technical references were applied to perform specialized analyzes: a) Theological and thixotropic properties. P.7.0841.01 subsection 8.4.1

b) Cation exchange capacity (CIC). API 13B-1 Chapter 10

c) Percent (%) of linear expansion. P.7.0841.01

d) Physical-chemical properties. Internal Procedure of Tecnología Integral en Fluidos de Perforación, S.A. from C.V. The fluid is designed to drill low and medium clay formations, but it is not limited to this type of well formation as long as the operation is warranted, and to drill the clay areas with the drilling fluid BASE POLYMERIC SEA WATER BASED WITH CHLORIDE OF POTASSIUM called SP-KCL®, which meets the Theological technical requirements to achieve hauling and suspension of cuts, filtering control, lubricity, clays inhibition.

The fluid of the present invention is mainly composed of seawater, liquid polymer products of new technological generation with high performance and easy preparation and rapid homogenization that minimizes ship logistics, ensuring the continuous supply of fluid volume during the drilling, to avoid non-productive times, guaranteeing the descent of the casing pipes in the estimated time, without operational logistic delays.

The drilling fluid BASE POLYMERIC SEA WATER WITH POTASSIUM CHLORIDE called SP-KCL® of the present invention, is designed for areas of clay from 15.0 to 50.0 meq / 100 milligrams of clay, with the proposed concentration "base "and can control more clays of high reactivity, as well as other types of wells. It also contemplates a range of high performance liquid inhibitors, to control the problems of swelling of the formation, clays that cause the dispersion of the walls of the formation, and the problems of colloidal fine solids, all these problems found in the perforation of clay areas, preventing and controlling the accretion and / or embolization of the auger and drilling tools. It has the control of lubricity in margins similar to those of oil based fluids on the market, the fluid of the present invention has in its formulation an excellent corrosion inhibitor as a secondary function for drilling pipes, the same product that gives us the advantage of providing high alkalinity and controlling the acid gases of the formation such as CO ₂ , CO, CH ₄ , H ₂ S (bitter gases).

The fluid of the present invention also has in its formulation the calcium carbonate bridging material with three types of granulometry, in order to ensure a good control of the stability of the hole for clay-sandy areas or other wells. DEVELOPMENT OF LABORATORY TESTS.

The rock-fluid interaction tests of the system, such as linear expansion and dispersion, were carried out. Likewise, the reactivity of the received sample and the physical-chemical analysis of the system called SP-KCL® were determined. DETERMINATION OF Rheological and Thixotropic Properties.

The physicochemical and theological analyzes of the system were performed, after stabilizing the system called SP-KCL®.

For 16.0 h, the temperature of analysis of the Theological and thixotropic properties is 120.0 ° F (49.0 ° C) at ambient pressure.

API filtering was carried out for 30.0 min. at 100.00 psi (690.00 KPa) pressure.

The pH of the mixture was determined using a potentiometer at room temperature.

CAPACITY OF CATIÓNICO EXCHANGE (CIC). It refers to an estimate of the cation exchange capacity of drilling solids (cuts, core). It is based on the fact that the reactive parts of the clays absorb methylene blue, thus determining the Cation Exchange Capacity. According to API 13B-1 methodology, in its chapter 10; The final point of the titration that allows us to determine the Cation Exchange Capacity is when a light blue halo appears around the sample of suspended solids taken. It is reported as milli equivalents / 100 g of sample.

PERCENT (%) OF LINEAR EXPANSION.

The linear increase is determined due to the hydration of a tablet manufactured with perforation cut, core or synthetic clay when in contact with the drilling fluid. The maximum specification is 25% (P.7.0841.01) after 1200.00 minutes (20.00 h). In this case, the sample was crushed, screened in an API 200.00 mesh and the tablets were made in a compactor at 10,000.00 psi for 1.5 h. RESULTS, ANALYSIS AND OBSERVATIONS.

REOLOGICAL AND PHYSICAL-CHEMICAL PROPERTIES.

The results of the rheologies and the initial physical-chemical analyzes were as follows: Table 2. Results obtained for rheologies and physical-chemical analyzes.

Parameter Base formulation

L600 rpm 44.00

L300 rpm 32.00

L200 rpm 27.00

L100 rpm 20.00

L6 rpm 9.00

L3 rpm 7.00

Plastic viscosity (cP) 12.00

Transfer point (Ib / 100 ft ² ) 20.00

pH 9.47

API filtering (ce) 10.2

CAPACITY OF CATIÓNICO EXCHANGE (CIC).

In the "Practical Guide for Fluid Selection" of PEMEX Exploration and Production (PEP), the clay is classified according to its Methylene Blue Capacity, represented by the following table:

Table 3. Capacity of claye methylene blue and its cation exchange capacity.

CAPITAL EXCHANGE CAPACITY

CLASSIFICATION

[meq / 100 g]

0.0-8.0 Non-reactive

Mediumly

9.0-18.0

Reagent

19.0-30.0 Reagent

> 30.0 Very Reactive

(Source: PEP).

Given the result of 35 milliequivalents / 100 g, the sample is considered Very Reactive PERCENT (%) OF LINEAR EXPANSION.

The results obtained from the linear expansion test were:

Table 4. Percent (%) of linear expansion.

As can be seen from the graph in figure 1, the SP-KCL® fluid is stable throughout the entire test, obtaining a result of 18.5% of total linear expansion, at the end of 20.0 h or 1200 , 00 min. This final value does not exceed the 25.0% requested by the technical reference p.7.0841.01

CONCLUSIONS OF THE TESTS.

As can be seen, the results of the rock-fluid interaction of the SP-KCL® system and the sample of the Varadero VDW1009 well field are satisfactory, since none exceeds the maximum value indicated in the technical reference P.7.0841.01

The training sample provided is considered a very reactive sample, since the value of the cation exchange capacity was high, 35 milliequivalents / 100 g.

Any change in the conditions described in this report will require a new evaluation.

Claims

Polymeric seawater-based fluid with potassium chloride for drilling offshore wells and offshore wells, comprising:

Seawater that considering a dam or tank selected for preparation, up to 80.00% of its capacity, considering a volume of 1 m ³ of seawater to be prepared from the fluid, depending on its density;

An alkalizing agent, such as an amine in a concentration of 0.5 to 6.00 L / m ³ ;

A mechanical inhibitor, such as potassium chloride in a concentration of 5.00 to 120 Kg / m ³ ;

A chemical inhibitor, such as an inhibitor based on amines and glycol in a concentration of 1.00 to 8.00

L / m ³ ;

A dispersion inhibitor, such as partially hydrolyzed polyacrylamide in a concentration of 0.5 to 8.00 L / m ³ ;

A filtrate reducer, such as a polyanionic cellulose in suspension in a concentration of 0.5 to 24.00 L / m ³ ;

A polymeric viscosifier, such as a suspension biopolymer in a concentration of 0.50 to 25.00 L / m ³ ;

A densifying material in a concentration necessary to the operation of the well of Kg per m ³ .

Polymeric seawater-based fluid with potassium chloride for drilling offshore wells and offshore wells, in accordance with claim 1, characterized in that it comprises a bridging agent, such as calcium carbonate of Malla 70, Malla 200 and Malla 325 and It is in a concentration of 15 Kg / m ³ each, this concentration can be adjusted according to the operation of each well.

The use of a polymeric water-based fluid with potassium chloride for drilling offshore wells and offshore wells as claimed in claim 1, in the drilling operation in an underground formation at an average depth of between +250, 00 to 1,360.00 m vertical below sea level, with drilling operating temperatures between 50.00 ° C to 90.00 ° C, with bottom operating pressures of +1.935.00 Kg / cm ² .

SUMMARY

The present invention relates to a polymeric seawater base fluid with potassium chloride for drilling offshore wells and offshore wells, the fluid is designed to drill low and medium clay formations, but is not limited to this type of water formation. wells if the operation justifies it, in the preferred embodiment of the invention it is used to drill the areas of clays with the high performance fluid based on polymeric seawater with potassium chloride, the present invention meets the Theological technical requirements to achieve the hauling and suspension of clippings, filtering control, lubricity, clays inhibition. The fluid of the present invention is mainly composed of seawater, liquid polymer products of new technological generation with high performance and easy preparation and rapid homogenization that minimizes ship logistics, ensuring the continuous supply of fluid volume during the drilling, to avoid non-productive times, guaranteeing the descent of the casing pipes in the estimated time, without operational logistic delays.